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BEGIN:VEVENT
SUMMARY:Suvrat Raju (ICTS\, Bengaluru)
DTSTART:20200504T093000Z
DTEND:20200504T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/1
DESCRIPTION:Title: The holographic nature of null infinity\nby Suvrat Raju (IC
TS\, Bengaluru) as part of ICTS String Seminars\n\n\nAbstract\nI will argu
e that a careful examination of the low energy properties of quantum gravi
ty\, together with reasonable assumptions about the UV theory\, leads to i
nsights into the origin of holography in anti-de Sitter space. The same te
chniques also lead to a clear conjecture about how quantum information is
localized in asymptotically flat spacetimes. The conjecture is that\, in q
uantum gravity\, all information about massless excitations can be obtaine
d from an infinitesimal neighbourhood of the past boundary of future null
infinity and does not require observations over all of future null infini
ty. In the context of the information paradox\, this suggests that the fin
e-grained von Neumann entropy of the state defined on a segment (-\\infty\
,u) of future null infinity is independent of u. This conjecture also impl
ies that the oft-discussed "Page curve" may be a misleading target to aim
for in analyses of black hole evaporation.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matteo Baggioli (IFT UAM-CSIC)
DTSTART:20200506T093000Z
DTEND:20200506T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/2
DESCRIPTION:Title: From Hydrodynamics to Viscoelasticity in Holography and beyond
...\nby Matteo Baggioli (IFT UAM-CSIC) as part of ICTS String Seminars
\n\n\nAbstract\nHow to construct a holographic model for viscoelastic mate
rials ?\n\nWhy can that be useful and for what purpose ?\nWhich is the hyd
rodynamics behind these models ?\nWhat do these models have in common with
quasicrystals ?\nWhat is a diffusive Goldstone mode and when does it appe
ar ?\nHow and in which sense are solids different from fluids ?\nWhat do t
heory and experiments in confined fluids tell us ?\nHow do glasses and Wey
l semimetals sound ?\n\nThese are the questions that I will discuss with
you during my talk!\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gautam Mandal (TIFR\, Mumbai)
DTSTART:20200513T093000Z
DTEND:20200513T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/3
DESCRIPTION:Title: Holographic interpretation of Bulk entanglement entropy\nby
Gautam Mandal (TIFR\, Mumbai) as part of ICTS String Seminars\n\n\nAbstra
ct\nWe propose a holographic interpretation of entanglement entropy (EE) o
f a spatial subregion A in the bulk\, in terms of the reduced density matr
ix for an appropriate sub algebra of observables\nin the boundary field th
eory/boundary quantum mechanics. The construct in the boundary theory corr
esponds to partitioning of the target space and is called a target space E
E. We discuss this in the context of supergravity dual of Dp brane field
theories\, in particular for D0 brane quantum mechanics. We find qualitat
ive agreement between the bulk and boundary calculations.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Maldacena (IAS\, Princeton)
DTSTART:20200522T113000Z
DTEND:20200522T123000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/4
DESCRIPTION:Title: Magnetic black holes\nby Juan Maldacena (IAS\, Princeton) a
s part of ICTS String Seminars\n\n\nAbstract\nWe discuss properties of mag
netically charged black holes in the\nStandard Model. We will discuss how
the electroweak symmetry is restored\naround the black hole. In addition\,
the Hawking evaporation rate is\ngreatly enhanced by a factor of the char
ge of the black hole.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Leopoldo Pando Zayas (University of Michigan)
DTSTART:20200527T103000Z
DTEND:20200527T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/5
DESCRIPTION:Title: Precision microstate counting of AdS black hole entropy\nby
Leopoldo Pando Zayas (University of Michigan) as part of ICTS String Semi
nars\n\n\nAbstract\nI will describe how within eleven dimensional supergra
vity one can compute the logarithmic correction to the Bekenstein-Hawking
entropy of certain magnetically charged asymptotically AdS$_4$ black holes
with arbitrary horizon topology. The result perfectly agrees with the du
al field theory computation of the topologically twisted index in ABJM th
eory and in certain theories obtained from M5 wrapping a hyperbolic 3-mani
fold. The extension to rotating\, electrically charged AdS$_4$ black holes
and the dual superconformal index will also be discussed.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Per Kraus (UCLA)
DTSTART:20200604T160000Z
DTEND:20200604T170000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/6
DESCRIPTION:Title: Anomalous Dimensions from Thermal AdS Partition Functions\n
by Per Kraus (UCLA) as part of ICTS String Seminars\n\n\nAbstract\nI will
present an efficient method for computing thermal partition functions of w
eakly coupled scalar fields in AdS. We consider quartic contact interactio
ns and show how to evaluate the relevant two-loop vacuum diagrams without
performing any explicit AdS integration\, the key step being the use of Ka
llen-Lehmann type identities. This leads to a simple method for extracting
double-trace anomalous dimensions in any spacetime dimension\, recovering
known first-order results in a streamlined fashion.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Larus Thorlacius (University of Iceland)
DTSTART:20200608T093000Z
DTEND:20200608T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/7
DESCRIPTION:Title: Page curves in asymptotically flat spacetime\nby Larus Thor
lacius (University of Iceland) as part of ICTS String Seminars\n\n\nAbstra
ct\nIf black hole evaporation is a unitary process\, the entanglement entr
opy between the \noutgoing Hawking radiation and the quantum state describ
ing the remaining black hole \nis expected to follow a so-called Page curv
e as a function of time. A Page curve for an \nevaporating black hole in a
symptotically flat spacetime can be computed analytically by\nadapting the
Quantum Ryu-Takayanagi (QRT) proposal to a solvable two-dimensional \ndil
aton gravity theory. The associated Page time is found to be one third of
the black \nhole lifetime\, at leading order in semi-classical corrections
. A Page curve can also be \nobtained for a semi-classical eternal black h
ole\, where energy loss due to Hawking \nevaporation is balanced by an inc
oming energy flux.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zhenbin Yang (Stanford)
DTSTART:20200610T033000Z
DTEND:20200610T043000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/8
DESCRIPTION:Title: Finite-cutoff JT gravity and self-avoiding loops\nby Zhenbi
n Yang (Stanford) as part of ICTS String Seminars\n\n\nAbstract\nWe study
quantum JT gravity at finite cutoff using a mapping to the statistical mec
hanics of a self-avoiding loop in hyperbolic space\, with positive pressur
e and fixed length. The semiclassical limit (small $G_{N}$) corresponds to
large pressure\, and we solve the problem in that limit in three overlapp
ing regimes that apply for different loop sizes. For intermediate loop siz
es\, a semiclassical effective description is valid\, but for very large o
r very small loops\, fluctuations dominate. For large loops\, this quantum
regime is controlled by the Schwarzian theory. For small loops\, the effe
ctive description fails altogether\, but the problem is controlled using a
conjecture from the theory of self-avoiding walks.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoff Penington (Stanford University)
DTSTART:20200624T033000Z
DTEND:20200624T043000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/9
DESCRIPTION:Title: Replica Wormholes\, Entanglement Wedges and the Black Hole Info
rmation Paradox\nby Geoff Penington (Stanford University) as part of I
CTS String Seminars\n\n\nAbstract\nHawking famously argued\, based on semi
classical calculations\, that the radiation from evaporating black holes i
s always perfectly thermal and contains no information about the matter th
at fell in. Such a result is inconsistent with the unitarity of quantum me
chanics. In this talk\, I will argue that a more careful replica trick cal
culation shows that the gravitational path integral becomes dominated at l
ate times by saddles containing spacetime wormholes. These wormholes cause
the entropy to decrease after the Page time\, consistent with unitarity\,
and allow information to escape from the interior of the black hole. In v
ery simple toy models\, we can evaluate the path integral exactly\, and se
e the information emerge. In more realistic black holes\, the full wormhol
e solutions cannot be found explicitly. However\, their existence\, and th
eir most important consequences\, can be derived by studying the location
and properties of a non-trivial ‘quantum extremal surface’ in the orig
inal Hawking solution.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nabamita Banerjee (IISER\, Bhopal)
DTSTART:20200626T093000Z
DTEND:20200626T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/10
DESCRIPTION:Title: A 3D flat-space holography inspired by AdS3/CFT2 duality\n
by Nabamita Banerjee (IISER\, Bhopal) as part of ICTS String Seminars\n\n\
nAbstract\nI shall mostly talk about the status of flat-space holography i
n three space time dimensions. The works are in parallel to AdS3/CFT2 dual
ity. I shall end with the open ends in the field.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sean Hartnoll (Stanford University)
DTSTART:20200723T123000Z
DTEND:20200723T133000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/11
DESCRIPTION:Title: Bootstrapping Matrix Quantum Mechanics\nby Sean Hartnoll (
Stanford University) as part of ICTS String Seminars\n\n\nAbstract\nMatrix
quantum mechanics theories are at the heart of holography\, but only the
simple case of a single matrix has been tractable. We have developed a new
method to calculate the spectrum and expectation values of operators in m
atrix quantum mechanics\, including with multiple matrices. Firstly\, we r
elate the expectation values of simple operators to those of more complica
ted operators. We then impose certain positivity constraints on the longer
operators. This is seen to strongly constrain the simple expectation valu
es. Using this method\, we easily reproduce the known solution of single-m
atrix quantum mechanics\, and then go on to obtain new results on the grou
nd state of two-matrix quantum mechanics. This talk is based on 2004.10212
.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arnab Priya Saha (HRI)
DTSTART:20200617T093000Z
DTEND:20200617T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/12
DESCRIPTION:Title: Double soft theorem in generalized bi-adjoint scalars\nby
Arnab Priya Saha (HRI) as part of ICTS String Seminars\n\n\nAbstract\nIn C
HY formalism\, scattering equations map the kinematic space of Mandelstam
invariants to the points on $\\mathbb{CP}^{1}$. Recently Cachazo\, Early\
, Guevara and Mizera have introduced generalization to the scattering equa
tions on higher dimensional projective spaces\, $\\mathbb{CP}^{k-1}$. Bi-a
djoint scalar amplitude is a well studied example of this generalisation.
We study double soft limits of the generalised bi-adjoint scalar amplitud
es for $k=3$. \n \nThis talk is based on the work in progress with Md. Abh
ishek\, Subramanya Hegde and Dileep P. Jatkar\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoffrey Compere (Université libre de Bruxelles)
DTSTART:20200619T093000Z
DTEND:20200619T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/13
DESCRIPTION:Title: The BMS group in (A)dS\nby Geoffrey Compere (Université l
ibre de Bruxelles) as part of ICTS String Seminars\n\n\nAbstract\nRecent w
ork has uncovered interesting connections between memory effects\, soft th
eorems and BMS asymptotic symmetries in the infrared structure of asymptot
ically flat gravity. In this talk\, I will present the AdS/dS generalizati
on of the BMS symmetries. I will discuss the realization of these “Lambd
a-BMS” symmetries as a surface charge algebra. I will also show that the
asymptotically flat BMS surface charge algebra is recovered in the asympt
otically flat limit only after adding corner terms in the variational prin
ciple in addition to the standard holographic counterterms.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Douglas Stanford (Stanford)
DTSTART:20200708T033000Z
DTEND:20200708T043000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/14
DESCRIPTION:Title: On the density matrix of the Hawking radiation\nby Douglas
Stanford (Stanford) as part of ICTS String Seminars\n\n\nAbstract\nWe set
up the computation of the density matrix of the Hawking radiation by comp
uting inner products of black hole states projected onto different histori
es of Hawking radiation. A simple computation of these inner products sugg
ests that an ensemble average is implicit in the simple gravity descriptio
n.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tom Hartman (Cornell)
DTSTART:20200715T120000Z
DTEND:20200715T130000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/15
DESCRIPTION:Title: Holographic duality for averaged free CFTs\nby Tom Hartman
(Cornell) as part of ICTS String Seminars\n\n\nAbstract\nI will describe
recent progress on the connections among the conformal bootstrap\, the sph
ere packing problem\, and quantum gravity in three dimensions. This leads
us toward a holographic duality between Narain CFTs averaged over moduli a
nd a Chern-Simons-like theory of "U(1) gravity"\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Subhroneel Chakrabarti (The Institute of Mathematical Sciences (IM
Sc)\, Chennai)
DTSTART:20200821T093000Z
DTEND:20200821T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/16
DESCRIPTION:Title: Pure Spinor Superstrings: Massive States\nby Subhroneel Ch
akrabarti (The Institute of Mathematical Sciences (IMSc)\, Chennai) as par
t of ICTS String Seminars\n\n\nAbstract\nPure Spinor formulation\, introdu
ced by Nathan Berkovits 20 years ago\, is the only known Super-Poincare co
variant worldsheet formulation of superstring theory. The last two decades
saw pure spinor formulation emerge as the most efficient way to compute s
tring amplitudes\, especially at higher loop levels. However\, most of the
se successes revolved around external massless states and the massive stat
es remained largely unexplored. In this talk\, I will describe the recent
development in understanding the massive states of superstrings in pure sp
inor formalism\, as carried out in a series of works by me and my collabor
ators. We will present the first proposal for systematic covariant constru
ction of massive vertex operators and discuss how that proposal lead to th
e construction of integrated massive vertex for the first time\, as well a
s its fully covariant theta expansion. With these new results\, we will al
so explain how for the first time an explicit equivalence of pure spinor a
nd the well-known RNS formalism for massive states was achieved. I will as
sume no prior knowledge of pure spinor formulation from the audience and s
pend some time introducing this formalism to make the talk more accessible
to a comparatively larger audience.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:R Loganayagam (ICTS\, Bengaluru)
DTSTART:20200422T093000Z
DTEND:20200422T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/17
DESCRIPTION:Title: Open QFTs from holography\nby R Loganayagam (ICTS\, Bengal
uru) as part of ICTS String Seminars\n\n\nAbstract\nIn this talk\, I will
outline a formalism to study open quantum field theories using holographic
methods. More precisely\, I will consider a quantum field theory (the sys
tem) coupled to a holographic field theory at finite temperature (the envi
ronment). The aim here is to integrate out the holographic environment wit
h an aim of obtaining an effective dynamics for the resulting open quantum
field theory. This is done using semiclassical gravitational Schwinger-Ke
ldysh saddle geometries obtained by complexifying black hole spacetimes.
In addition to shedding light on open quantum systems coupled to strongly
correlated thermal environments\, these results also provide a principled
computation of Schwinger-Keldysh observables in gravity and holography. I
n particular\, these influence functionals capture both the dissipative ph
ysics of black hole quasinormal modes\, as well as that of the fluctuation
s encoded in outgoing Hawking quanta\, and interactions between them.\n\n\
nThis talk will be based on https://arxiv.org/abs/2004.02888\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shamik Banerjee (IOP\, Bhubaneswar)
DTSTART:20200429T093000Z
DTEND:20200429T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/18
DESCRIPTION:Title: BMS symmetry of celestial OPE\nby Shamik Banerjee (IOP\, B
hubaneswar) as part of ICTS String Seminars\n\n\nAbstract\nIn this talk\,
we study the BMS symmetry of the celestial\nOPE of two positive helicity g
ravitons in Einstein theory in four\ndimensions. The celestial OPE is obta
ined by Mellin transforming the\nscattering amplitude in the (holomorphic)
collinear limit. The collinear\nlimit at leading order gives the singular
term of the celestial OPE. We\ncompute the first subleading correction to
the OPE by analysing the four\ngraviton scattering amplitude directly in
Mellin space. The subleading\nterm can be written as a linear combination
of BMS descendants with the\nOPE coefficients determined by BMS algebra an
d the coefficient of the\nleading term in the OPE. This can be done by def
ining a suitable BMS\nprimary state. We find that among the descendants\,
which appear at the\nfirst subleading order\, there is one which is create
d by holomorphic\nsupertranslation with a simple pole on the celestial sph
ere.\n\n This talk is based on https://arxiv.org/abs/2002.00975\n
(https://doi.org/10.1007/JHEP04(2020)130 )\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mark Van Raamsdonk (UBC)
DTSTART:20200729T033000Z
DTEND:20200729T043000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/19
DESCRIPTION:Title: Holo-ween\nby Mark Van Raamsdonk (UBC) as part of ICTS Str
ing Seminars\n\n\nAbstract\nWe argue that given holographic $CFT_1$ in som
e state with a dual spacetime geometry $M$\, and given some other hologra
phic $CFT_2$\, we can find states of $CFT_2$ whose dual geometries closely
approximate arbitrarily large causal patches of M\, provided that $CFT_1$
and $CFT_2$ can be non-trivially coupled at an interface. Our $CFT_2$ sta
tes are "dressed up as" states of CFT1: they are obtained from the origina
l $CFT_1$ state by a regularized quench operator defined using a Euclidean
path-integral with an interface between $CFT_2$ and $CFT_1$. Our results
are consistent with the idea that the precise microscopic degrees of freed
om and Hamiltonian of a holographic $CFT$ are only important in fixing the
asymptotic behavior of a dual spacetime\, while the interior spacetime of
a region spacelike separated from a boundary time slice is determined by
more universal properties (such as entanglement structure) of the quantum
state at this time slice. Our picture requires that low-energy gravitation
al theories related to $CFTs$ that can be non-trivially coupled at an inte
rface are part of the same non-perturbative theory of quantum gravity.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Derek Teaney (SUNY)
DTSTART:20200805T113000Z
DTEND:20200805T123000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/20
DESCRIPTION:Title: Transport and hydrodynamics in almost the chiral limit.\nb
y Derek Teaney (SUNY) as part of ICTS String Seminars\n\n\nAbstract\nFirst
I will briefly review lattice data on the QCD phase transition\, which sh
ows that real world QCD at the physical pion mass is close enough to the c
hiral limit that the $O_4$ phase transition describes several features of
the QCD crossover. Next I describe the appropriate hydrodynamic theory in
the spontaneously broken chiral limit\, where the pions must be included
in the list of hydrodynamic fields\, and the theory is a prototype for non
-abelian superfluids more generally. In the real world the mass of the pio
n is finite\, and thus theory is superfluid like at short distances\, but
normal fluid like at long distances. The superfluid modes can be integrate
d out by evaluating the appropriate hydrodynamic loop\, leaving calculable
corrections to the transport parameters of the normal fluid. Alternative
ly\, one can develop a kinetic equation for the soft pion modes\, which ca
n be used to evaluate these corrections. I discuss how these corrections
scale near the chiral critical point. Finally\, I point out a few probl
ems that normal-fluid hydro simulations have in describing the observed s
oft pion yields in heavy ion collisions. I suggest that the superfluid th
eory can help to resolve these residual discrepancies with the otherwise r
emarkably successful hydro model.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Raghu Mahajan (IAS\, Princeton)
DTSTART:20200826T043000Z
DTEND:20200826T053000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/21
DESCRIPTION:Title: A Tutorial on Entanglement Island Computations\nby Raghu M
ahajan (IAS\, Princeton) as part of ICTS String Seminars\n\n\nAbstract\nIn
this talk we will present details of quantum extremal surface computation
s in a simple setup\, demonstrating the role of entanglement islands in re
solving entropy paradoxes in gravity. The setup involves eternal AdS2 blac
k holes in thermal equilibrium with auxiliary bath systems. We will also
describe the extension of this setup to higher dimensions using Randall-Su
ndrum branes.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atish Dabholkar (ICTP)
DTSTART:20200812T093000Z
DTEND:20200812T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/22
DESCRIPTION:Title: Three Avatars of Mock Modularity\nby Atish Dabholkar (ICTP
) as part of ICTS String Seminars\n\n\nAbstract\nMock theta functions were
introduced by Ramanujan in his famous last letter to Hardy in 1920 but we
re properly understood only recently with the work of Zwegers in 2002. I w
ill describe three manifestations of this apparently exotic mathematics in
three important physical contexts of holography\, topology and dualit
y where mock modularity is essential to exhibit modular symmetries expe
cted from the $AdS_3/CFT_2$ holographic equivalence in quantum gravity
and the S-duality symmetry of four-dimensional quantum gauge theorie
s. \nIn particular\, I will show that the completion of mock modular form
s occurring in these contexts satisfy a holomorphic anomaly equation.
This phenomenon can be related to the holomorphic anomaly of the ellipt
ic genus of a two-dimensional noncompact supersymmetric sigma model\, and
in a simpler context of quantum mechanics to the Atiyah-Patodi-Singer et
a invariant.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pavel Putrov (ICTP)
DTSTART:20200819T093000Z
DTEND:20200819T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/23
DESCRIPTION:Title: Holomorphic anomaly in Vafa-Witten theory\nby Pavel Putrov
(ICTP) as part of ICTS String Seminars\n\n\nAbstract\nVafa-Witten theory
is a topologically twisted version of 4d N=4 super Yang-Mills theory. In m
y talk I will tell how to derive a holomorphic anomaly equation for its pa
rtition function on a Kaehler 4-manifold with b_2^+=1 and b_1=0 from the p
ath integral of the effective theory on the Coulomb branch. I will also br
iefly mention an alternative but somewhat similar computation of the same
holomorphic anomaly in the effective 2d theory obtained by compactificatio
n of the corresponding 6d (2\,0) theory on the 4-manifold. The talk is bas
ed on a joint work with A. Dabholkar and E. Witten.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Netta Englehardt (MIT)
DTSTART:20200902T133000Z
DTEND:20200902T143000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/24
DESCRIPTION:Title: Free Energy from Replica Wormholes\nby Netta Englehardt (M
IT) as part of ICTS String Seminars\n\n\nAbstract\nRecent developments on
the black hole information paradox have shown that Euclidean wormholes —
so called “replica wormholes’’ can dominate the von Neumann entropy
as computed by a gravitational path integral\, and that inclusion of thes
e wormholes results in a unitary Page curve. This development raises some
puzzles from the perspective of factorization\, and has raised questions r
egarding what the gravitational path integral is computing. In this talk\,
I will focus on understanding the relationship between the gravitational
path integral and the partition function via the gravitational free energy
(more generally the generating functional). A proper computation of the f
ree energy requires a replica trick distinct from the usual one used to co
mpute the entropy. I will show that in JT gravity there is a regime where
the free energy computed without replica wormholes is pathological. Intere
stingly\, the inclusion of replica wormholes is not quite sufficient to re
solve the pathology: an alternative analytic continuation is required. I w
ill discuss the implications of this for various interpretations of the gr
avitational path integral (e.g. as computing an ensemble average) and also
mention some parallels with spin glasses.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sujay Ashok (IMSc\, Chennai)
DTSTART:20200916T093000Z
DTEND:20200916T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/25
DESCRIPTION:Title: Surface Defects from Fractional Branes\nby Sujay Ashok (IM
Sc\, Chennai) as part of ICTS String Seminars\n\n\nAbstract\nWe show that
the Gukov-Witten defects of supersymmetric Yang-Mills theory can be realiz
ed in perturbative string theory. This is done by considering an orbifold
background of the Kanno-Tachikawa type and placing stacks of fractional D3
-branes whose world-volume partially extends along the orbifold directions
. In particular\, we show that turning on a constant background value for
some scalar fields in the closed string twisted sectors induces a non-triv
ial profile for the gauge field and one of the complex scalars of the worl
d-volume theory. This profile exactly matches the singular behavior that o
ne expects for a Gukov-Witten surface defect in the N=4 supersymmetric gau
ge theory.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Abhijit Gadde (TIFR)
DTSTART:20200923T093000Z
DTEND:20200923T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/26
DESCRIPTION:Title: Modularity of supersymmetric partition functions\nby Abhij
it Gadde (TIFR) as part of ICTS String Seminars\n\n\nAbstract\nIn this tal
k\, I will present a novel modular property of 4d N=1 supersymmetric parti
tion functions of supersymmetric theories with R-symmetry. It is a general
ization of the modular invariance of the supersymmetric partition function
of two-dimensional supersymmetric theories on a torus i.e. of the ellipti
c genus. It comes from requiring consistency of partition functions under
gluing and\, among other things\, can be used to rederive the supersymmetr
ic Cardy formula for four-dimensional gauge theories that has played a key
role in computing the entropy of supersymmetric black holes.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nima Arkani-Hamed (IAS\, Princeton)
DTSTART:20200710T130000Z
DTEND:20200710T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/27
DESCRIPTION:Title: Spacetime\, quantum mechanics and clusterhedra at Infinity
\nby Nima Arkani-Hamed (IAS\, Princeton) as part of ICTS String Seminars\n
\n\nAbstract\nElementary particle scattering is perhaps the most basic phy
sical process in Nature. The data specifying the scattering process define
s a "kinematic space"\, associated with the on-shell propagation of parti
cles out to infinity. By contrast the usual approach to computing scatteri
ng amplitudes\, involving path integrals and Feynman diagrams\, invokes au
xilliary structures beyond this kinematic space--local interactions in the
interior of spacetime\, and unitary evolution in Hilbert space. This desc
ription makes space-time locality and quantum-mechanical unitarity manifes
t\, but hides the extraordinary simplicity and infinite hidden symmetries
of the amplitudes\,g that have been uncovered over the past thirty years.
The past decade has seen the emergence of a new picture\, where scattering
amplitudes are seen as the answer to an entirely different sort of mathem
atical question involving "positive geometries" directly in the kinematic
space\, making surprising connections to total positivity\, combinatorics
and geometry of the grassmannian\, and cluster algebras. The hidden symmet
ries of amplitudes are made manifest in this way\, while locality and uni
tarity are seen as derivative notions\, arising from the "factorizing" bo
undary structure of the positive geometries. This was first see in the st
ory of "amplituhedra" and scattering amplitudes in planar N=4 SYM theory.
In the past few years\, a similar structure has been seen for non-superys
mmetric "bi-adjoint" scalar theories with cubic interactions\, in any numb
er of dimensions. The positive geometries through to one-loop order are gi
ven by "cluster polytopes"--generalized associahedra for finite-type clust
er algebras--with a simple description involving "dynamical evolution" in
the kinematic space. Extending these ideas involves understanding cluster
algebras associated with triangulations of general Riemann surfaces. These
cluster algebras are infinite\, reflecting the infinite action of mapping
class group. One of the manifestations of this infinity is that the "g-ve
ctor fan" of the cluster algebra is not space-filling\, making it impossib
le to define cluster polytopes\, and obstructing the connection with posit
ive geometries and scattering amplitudes. Remarkably\, incorporating non-c
luster variables\, associated with closed loops in the Riemann surfaces\,
suggests a natural way of modding out by the mapping class group\, canonic
ally compactifying the cluster complex\, and associating it with "clusterh
edron" polytopes. Clusterhedra are conjectured to exist for all surfaces\,
providing the positive geometry in kinematic space for scattering amplitu
des in the bi-adjoint scalar theory to all loop orders and all orders in t
he 1/N expansion. In this talk I will give an overview of this set of idea
s\, assuming no prior knowledge of scattering amplitudes or cluster alge
bras. My lectures at the ICTS workshop on scattering amplitudes later this
month\, will give a systematic\, self-contained exposition of all the phy
sical and mathematical ideas involved\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vijay Balasubramanian (University of Pennsylvania)
DTSTART:20200909T130000Z
DTEND:20200909T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/28
DESCRIPTION:Title: Euclidean wormholes\, baby universes\, and unitarity in quantu
m gravity\nby Vijay Balasubramanian (University of Pennsylvania) as pa
rt of ICTS String Seminars\n\n\nAbstract\nSpacetime wormholes in the Eucli
dean path integral for gravity represent the nucleation and annihilation o
f baby universes. In the first part of the seminar I show how their inclu
sion in the replica method preserves monogamy of entanglement and semiclas
sical unitarity. I apply the results to universes that have a positive co
smological constant. In the second part of the talk I extend a recently
introduced topological model of gravity with baby universes to include a s
um over spin structures. The results suggest that the gravitational path
integral with wormholes should be interpreted in terms of an ensemble of
dual theories. I conclude by discussing the apparent tension between th
ese effects of spacetime wormholes\, namely\, the restoration of unitarity
in manifestations of quantum entanglement in semiclassical gravity vs. th
e apparent need to describe gravitating systems in terms of a statistical
ensemble.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luca Delacretaz (University of Chicago)
DTSTART:20200930T140000Z
DTEND:20200930T150000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/29
DESCRIPTION:Title: Heavy Operators and Hydrodynamic Tails\nby Luca Delacretaz
(University of Chicago) as part of ICTS String Seminars\n\n\nAbstract\nTh
e late time physics of interacting QFTs at finite temperature is controlle
d by hydrodynamics. For CFTs this implies that heavy operators -- which ar
e generically expected to create thermal states -- can be studied semiclas
sically. We show that hydrodynamics universally fixes the OPE coefficients
C_{HH'L}\, on average\, of all neutral light operators with two non-ident
ical heavy ones\, as a function of the scaling dimension and spin of the o
perators. These methods can be straightforwardly extended to CFTs with glo
bal symmetries\, and generalize recent EFT results on large charge operato
rs away from the case of minimal dimension at fixed charge. We also revisi
t certain aspects of late time thermal correlators in QFT and other diffus
ive systems.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seok Kim (Seoul National University)
DTSTART:20201007T093000Z
DTEND:20201007T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/30
DESCRIPTION:Title: Black hole microstates and the index\nby Seok Kim (Seoul N
ational University) as part of ICTS String Seminars\n\n\nAbstract\nI will
explain the simple idea which allowed the recent microstate countings of B
PS AdS black holes.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Upamanyu Moitra (TIFR)
DTSTART:20201014T093000Z
DTEND:20201014T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/31
DESCRIPTION:Title: Near-Extremal Fluid Mechanics\nby Upamanyu Moitra (TIFR) a
s part of ICTS String Seminars\n\n\nAbstract\nThis talk concerns fluid mec
hanics corresponding to near-extremal black branes in anti-de Sitter space
time\, in an unconventional regime. In this regime\, in contrast with the
conventional one\, the temperature of the fluid is much smaller than the s
patial and temporal rates of variation of the various fluid parameters. It
turns out that Einstein-Maxwell equations admit a systematic perturbative
expansion even in the new regime. There are interesting new features for
fluid dynamics at low temperatures – non-localities in the constitutive
relations beyond first order in derivatives\, for example. My talk will fo
cus on a simple model which will illustrate the essential features of the
near-extremal fluid-gravity correspondence. I will also describe some key
results for the actual fluid system dual to the gravitational theory.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edward Witten (IAS\, Princeton)
DTSTART:20200717T120000Z
DTEND:20200717T130000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/32
DESCRIPTION:Title: Deformations of JT gravity and matrix models\nby Edward Wi
tten (IAS\, Princeton) as part of ICTS String Seminars\n\n\nAbstract\nRece
ntly it was shown by Saad\, Shenker\, and Stanford that JT gravity in two
dimensions is dual not to any particular quantum system but to a random en
semble of quantum systems. I will explain that if one deforms JT gravity
by adding a self-coupling of the scalar field\, the resulting model is st
ill dual to a random ensemble of quantum systems\, with a different densit
y of energy levels. I will also briefly describe work of Maxfield and T
uriaci\, who made a similar analysis in two dimensions and related it to i
ssues in three-dimensional gravity.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cumrun Vafa and Miguel Montero (Harvard University)
DTSTART:20200904T120000Z
DTEND:20200904T130000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/33
DESCRIPTION:Title: The Swampland in d>6\nby Cumrun Vafa and Miguel Montero (H
arvard University) as part of ICTS String Seminars\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mithat Unsal (NCSU)
DTSTART:20201021T093000Z
DTEND:20201021T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/34
DESCRIPTION:Title: Strongly coupled QFT dynamics via TQFT coupling\nby Mithat
Unsal (NCSU) as part of ICTS String Seminars\n\n\nAbstract\nWe consider a
class of quantum field theories and quantum\nmechanics\, which we couple
to topological QFTs\, in order to classify\nnon-perturbative effects in th
e original theory. The TQFT structure\narises naturally from turning on a
classical background field for a\ndiscrete global symmetry. In SU(N) Yang-
Mills theory coupled to\nTQFT\, the non-perturbative expansion parameter i
s\nexp[-S_I/N] both in the semi-classical weak coupling domain and\nstrong
coupling domain\, corresponding to a\nfractional topological charge and a
ction configurations. To classify\nthe non-perturbative effects in origina
l SU(N) theory\, we must use\nPSU(N) bundle and lift configurations (criti
cal points at infinity)\nfor which there is no obstruction back to SU(N).
These provide a\nrefinement of instanton sums: integer topological charge\
, but\ncrucially fractional action configurations contribute\, providing a
\nTQFT protected generalization of resurgent semiclassical expansion to\ns
trong coupling.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Noppadol Mekareeya (INFN Milano-Bicocca)
DTSTART:20201028T093000Z
DTEND:20201028T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/35
DESCRIPTION:Title: Supersymmetry enhancement in 3d S-fold SCFTs\nby Noppadol
Mekareeya (INFN Milano-Bicocca) as part of ICTS String Seminars\n\n\nAbstr
act\nA local SL(2\,Z) transformation on the Type IIB brane configuration g
ives rise to an interesting class of 3d superconformal field theories\, kn
own as the S-fold SCFTs. One of the interesting features of such a theory
is that\, in general\, it does not admit a conventional Lagrangian descrip
tion. Nevertheless\, it can be described by a quiver diagram with a buildi
ng block being an SCFT known as the T(U(N)) theory. In this talk\, we disc
uss various interesting properties of the S-fold theories\, including supe
rsymmetry enhancement in the infrared as well as several interesting duali
ties. This talk will have a different emphasis than previous talks with
the similar title and abstract.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Soumyadeep Chaudhuri (Hebrew University)
DTSTART:20201104T093000Z
DTEND:20201104T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/36
DESCRIPTION:Title: Thermal order in large N conformal gauge theories\nby Soum
yadeep Chaudhuri (Hebrew University) as part of ICTS String Seminars\n\n\n
Abstract\nOur experience with many physical systems (eg. magnets) tells us
that usually when a symmetry is spontaneously broken at low temperatures\
, it is restored upon increasing the temperature sufficiently. The abunda
nce of such systems raises the question of whether this is a universal fea
ture of all quantum systems. In this talk\, I will present examples of (3+
1)-dimensional non-supersymmetric large N gauge theories which demonstrate
violations of the above feature. I will argue that in the N tending to in
finity limit\, these theories have conformal manifolds which survive under
all loop corrections to the beta functions of the couplings. I will show
that under certain conditions\, a subset of points on such a conformal man
ifold demonstrates the spontaneous breaking of a global symmetry at all no
nzero temperatures. Furthermore\, I will demonstrate that this symmetry br
eaking is accompanied by the Higgsing of a subset of gauge bosons leading
the system to be in a persistent Brout-Englert-Higgs phase.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Julian Sonner (University of Geneva)
DTSTART:20201111T093000Z
DTEND:20201111T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/37
DESCRIPTION:Title: Causal symmetry breaking: late time physics of holographic qua
ntum chaos\nby Julian Sonner (University of Geneva) as part of ICTS St
ring Seminars\n\n\nAbstract\nQuantum chaotic systems are often defined via
the assertion that their spectral\nstatistics coincides with\, or is well
approximated by\, random matrix theory. In this\ntalk I will explain how
the universal content of random matrix theory emerges as the\nconsequence
of a simple symmetry-breaking principle and its associated Goldstone\nmode
s. This approach naturally leads to wormhole-like correlations in holograp
hy\, even for individual theories. \nFinally I will comment on very recent
results that allow us to extend the Goldstone effective-field-theory appr
oach to operator correlation functions\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rob Myers (Perimeter Institute)
DTSTART:20201125T093000Z
DTEND:20201125T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/39
DESCRIPTION:Title: Quantum Extremal Islands Made Easy\nby Rob Myers (Perimete
r Institute) as part of ICTS String Seminars\n\n\nAbstract\nWe illustrate
the appearance of quantum extremal islands in holographic setups in higher
dimensions. We emphasize the close parallel with the behaviour of hologra
phic entanglement entropy in more familiar settings.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chandramouli Chowdhury (ICTS-TIFR)
DTSTART:20200925T093000Z
DTEND:20200925T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/40
DESCRIPTION:Title: A physical protocol for observers near the boundary to obtain
bulk information in quantum gravity\nby Chandramouli Chowdhury (ICTS-T
IFR) as part of ICTS String Seminars\n\n\nAbstract\nWe consider a set of o
bservers who live near the boundary of global AdS\, and are allowed to act
only with simple low-energy unitaries and make measurements in a small in
terval of time. The observers are not allowed to leave the near-boundary r
egion. We describe a physical protocol that nevertheless allows these obse
rvers to obtain detailed information about the bulk state. This protocol u
tilizes the leading gravitational back-reaction of a bulk excitation on th
e metric\, and also relies on the entanglement-structure of the vacuum. Fo
r low-energy states\, we show how the near-boundary observers can use this
protocol to completely identify the bulk state. We explain why the protoc
ol fails completely in theories without gravity\, including non-gravitatio
nal gauge theories. This provides perturbative evidence for the claim that
one of the signatures of holography -- the fact that information about th
e bulk is also available near the boundary -- is already visible in semicl
assical gravity.\n\nThis is work done in collaboration with Olga Papadoula
ki and Suvrat Raju and the reference is: https://arxiv.org/abs/2008.01740.
\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Justin David (IISc)
DTSTART:20201202T093000Z
DTEND:20201202T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/41
DESCRIPTION:Title: Information theoretic measures in 2d CFT and their universal
properties\nby Justin David (IISc) as part of ICTS String Seminars\n\n
\nAbstract\nWe begin with a brief review of measures such as entanglement
entropy\, \nrelative entropy and techniques to evaluate them in 2d CFT. \
nWe then study the properties of these measures when the theory \nor the s
tate on which these measures are evaluated are deformed by \nthe symmetrie
s of the theory. The symmetries we focus are the \nVirasoro symmetries an
d higher spin symmetries. \nWe present 2 situations for which the deformat
ions result in universal \ncorrections to the information theoretic measur
es.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Soeren Schlichting (Bielefeld University)
DTSTART:20201216T093000Z
DTEND:20201216T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/43
DESCRIPTION:Title: Non-equilibrium QCD in heavy ion collisions\nby Soeren Sch
lichting (Bielefeld University) as part of ICTS String Seminars\n\n\nAbstr
act\nOver the past decades\, experiments at the Relativistic Heavy-Ion Col
lider (RHIC) and the Large Hadron Collider (LHC) have collected an overwhe
lming amount of evidence of the formation of a de-confined Quark-Gluon Pla
sma (QGP) \, and established a standard picture of the space-time evolutio
n of the QGP based on relativistic viscous hydrodynamics. While high-energ
y Heavy-Ion Collisions thus provide a unique laboratory to study strong-in
teraction matter under extreme conditions\, it has proven challenging to u
nderstand how the far-from equilibrium initial state eventually turns into
a nearly equilibrated plasma of quarks and gluons. In this talk I will hi
ghlight recent theoretical progress in understanding different thermalizat
ion mechanisms in QCD plasmas and address the question how an almost equil
ibrated Quark-Gluon plasma is created during the early stages of high-ener
gy collisions. I will also discuss how these studies provide new insights
into the range of applicability of dissipative fluid dynamics and the emer
gence of universal properties in out-of-equilibrium systems\, and if time
remains address some phenomenological consequences of the early time non-e
quilibrium dynamics.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Akhil Sivakumar (ICTS-TIFR)
DTSTART:20201118T053000Z
DTEND:20201118T063000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/44
DESCRIPTION:Title: Gravitational probes with memory\nby Akhil Sivakumar (ICTS
-TIFR) as part of ICTS String Seminars\n\n\nAbstract\nBlackholes are inter
esting mainly due to two reasons. The first is that they give rise to irre
versible dynamics - event horizons mark a region of no return. Secondly th
ey produce Hawking radiation. While the first dissipative behaviour is wel
l studied\, the physics of fluctuations or Hawking radiation is not. In th
is talk I will present preliminary results on understanding the real-time
Hawking fluctuations around an AdS blackbrane. The techniques we develop g
ive a clean separation of short lived and long lived dynamics of the black
brane.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pavel Kovtun (University of Victoria)
DTSTART:20210120T093000Z
DTEND:20210120T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/45
DESCRIPTION:Title: Hydrodynamics beyond hydrodynamics\nby Pavel Kovtun (Unive
rsity of Victoria) as part of ICTS String Seminars\n\n\nAbstract\nHydrodyn
amics is a well-established field with a venerable history. In\nthis talk\
, I will focus on two foundational aspects of hydrodynamics\nwhich have re
ceived renewed attention in recent years. 1) Do the\nequations of hydrodyn
amics even make sense? and 2) How do we describe\nlong-wavelength phenomen
a that hydrodynamics is supposed to describe but\nfails to?\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sudarshan Ananth (IISER\, Pune)
DTSTART:20210127T093000Z
DTEND:20210127T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/46
DESCRIPTION:Title: An intricate path to gravity\nby Sudarshan Ananth (IISER\,
Pune) as part of ICTS String Seminars\n\n\nAbstract\nSymmetry enhancement
s in supergravity are presented and the resulting consequences for pure gr
avity discussed.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rajesh Gopakumar (ICTS)
DTSTART:20210106T093000Z
DTEND:20210106T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/47
DESCRIPTION:Title: From Symmetric Product CFTs to AdS_3\nby Rajesh Gopakumar
(ICTS) as part of ICTS String Seminars\n\n\nAbstract\nHow exactly do large
N QFTs reassemble themselves into perturbative string theories? This talk
will focus on an example which explicitly illustrates a general program o
f how this can happen around a free field fixed point. Specifically\, we c
onsider n-point correlators in the symmetric product orbifold theory\, dua
l to tensionless strings on AdS_3\, in a Gross-Mende like limit of large c
onformal dimensions. These correlators are given in terms of branched cove
ring maps which we can exactly solve for in this limit\, via a map to a ma
trix model with a logarithmic potential. The spectral curve encoding the m
atrix model solution then naturally gives rise to an integral over the dua
l string moduli space through a special (Strebel) parameterization of the
latter. This is a precise realisation of what was proposed as the underlyi
ng mechanism for gauge-string duality in weakly coupled QFTS. Finally\, th
e integrand on the moduli space can be cast in a number of striking forms
including an action given by (the modulus of) the Schwarzian of the coveri
ng map\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christopher Mogni (UC Berkeley)
DTSTART:20210113T043000Z
DTEND:20210113T063000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/48
DESCRIPTION:Title: Large-N Expansion and String Theory Out of Equilibrium\nby
Christopher Mogni (UC Berkeley) as part of ICTS String Seminars\n\n\nAbst
ract\nString theory has been incredibly successful at describing both gaug
e and gravity systems in equilibrium\, whereby the vacuum state is assumed
to be eternal and static. While progress has been made in applying string
theory to non-equilibrium scenarios\, such as the fate of non-extremal bl
ack holes and early universe cosmology\, there is no framework for describ
ing string theory out of equilibrium. In this talk\, I will describe how t
he large-N expansion of field theories with matrix degrees of freedom put
on a closed time contour implies a refined topological worldsheet expansio
n for strings out of equilibrium.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Amirhossein Tajdini (UCSB)
DTSTART:20210205T133000Z
DTEND:20210205T143000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/49
DESCRIPTION:Title: Replica wormholes for an evaporating black hole\nby Amirho
ssein Tajdini (UCSB) as part of ICTS String Seminars\n\n\nAbstract\nQuantu
m extremal islands reproduce the unitary Page curve of an evaporating blac
k hole in JT gravity. In previous work\, this result was formally derived
by including replica wormholes in the gravitational path integral\, but th
e wormholes were not found explicitly\, or even fully defined\, for the ti
me-dependent geometries relevant to Hawking’s paradox. A technical chall
enge is that replica wormholes rely on a Euclidean path integral while the
quantum extremal islands of an evaporating black hole exist only in Loren
tzian signature. In this talk\, I will discuss how to construct these worm
holes for n ∼ 1 replicas and confirm that they lead to the island rule f
or the entropy.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ashoke Sen (HRI)
DTSTART:20210210T093000Z
DTEND:20210210T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/50
DESCRIPTION:Title: D-instanton amplitudes\nby Ashoke Sen (HRI) as part of ICT
S String Seminars\n\n\nAbstract\nD-instantons give non-perturbative contri
bution to string theory\namplitudes which can be computed using world-shee
t techniques. However the\nintegrals that appear in this computation often
have divergences from\ncorners of the moduli spaces which cannot be tamed
by the usual procedure\nof analytic continuation. We show how using insig
hts from string field\ntheory we can extract finite unambiguous results fr
om these apparently\ndivergent integrals.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michal P. Heller (AEI)
DTSTART:20210310T093000Z
DTEND:20210310T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/51
DESCRIPTION:Title: Spacetime as a quantum circuit\nby Michal P. Heller (AEI)
as part of ICTS String Seminars\n\n\nAbstract\nWe propose that finite cuto
ff regions of holographic spacetimes represent quantum circuits that map b
etween boundary states at different times and Wilsonian cutoffs\, and that
the complexity of those quantum circuits is given by the gravitational ac
tion. The optimal circuit minimizes the gravitational action. This is a ge
neralization of both the "complexity equals volume" conjecture to unoptimi
zed circuits\, and path integral optimization to finite cutoffs. Using too
ls from holographic $T\\bar{T}$\, we find that surfaces of constant scalar
curvature play a special role in optimizing quantum circuits. We also fin
d an interesting connection of our proposal to kinematic space\, and discu
ss possible circuit representations and gate counting interpretations of t
he gravitational action.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Tong (DAMTP)
DTSTART:20210317T093000Z
DTEND:20210317T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/52
DESCRIPTION:Title: How to Give Chiral Fermions a Mass\nby David Tong (DAMTP)
as part of ICTS String Seminars\n\n\nAbstract\nChiral fermions have the pr
operty that their left-handed and right-handed components transform differ
ently under some symmetry. Folklore suggests that it is impossible to give
such fermions a mass \nwithout breaking this symmetry. I'll show\, throug
h a number of examples\, why this folklore is wrong. In particular\, I'll
show how one generation of fermions in the Standard Model can get a mass w
ithout the need for a Higgs boson that breaks electroweak symmetry.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jorge Santos (DAMTP)
DTSTART:20210414T093000Z
DTEND:20210414T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/53
DESCRIPTION:Title: AdS Euclidean wormholes\nby Jorge Santos (DAMTP) as part o
f ICTS String Seminars\n\n\nAbstract\nWe explore the construction and stab
ility of asymptotically anti-de Sitter Euclidean wormholes in a variety of
models. In simple ad hoc low-energy models\, it is not hard to construct
two-boundary Euclidean wormholes that dominate over disconnected solutions
and which are stable (lacking negative modes) in the usual sense of Eucli
dean quantum gravity. Indeed\, the structure of such solutions turns out t
o strongly resemble that of the Hawking-Page phase transition for AdS-Schw
arzschild black holes\, in that for boundary sources above some threshold
we find both a `large' and a `small' branch of wormhole solutions with the
latter being stable and dominating over the disconnected solution for lar
ge enough sources. We are also able to construct two-boundary Euclidean wo
rmholes in a variety of string compactifications that dominate over the di
sconnected solutions we find and that are stable with respect to field-the
oretic perturbations. However\, as in classic examples investigated by Mal
dacena and Maoz\, the wormholes in these UV-complete settings always suffe
r from brane-nucleation instabilities (even when sources that one might ho
pe would stabilize such instabilities are tuned to large values). This ind
icates the existence of additional disconnected solutions with lower actio
n. We discuss the significance of such results for the factorization probl
em of AdS/CFT.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andreas Karch (UT Austin)
DTSTART:20210217T043000Z
DTEND:20210217T053000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/54
DESCRIPTION:Title: Information Transfer with a Gravitating Bath\nby Andreas K
arch (UT Austin) as part of ICTS String Seminars\n\n\nAbstract\nRecent pro
gress in our understanding of black hole evaporation\nhas mostly occurred
in the context of black holes coupled to an\nexternal\, non-gravitating ba
th. In order to compare and contrast to what\nhappens to black holes in as
ymptotically flat space it is imperative to\nunderstand whether the non-gr
avitating bath is just some external\nspectator or actively changes the ph
ysics in this system. Equivalently\,\none can wonder to what extent the re
sults generalize to the case of a\ngravitating bath. We use Randall-Sundru
m braneworlds\, and their\nholographic interpretation\, to answer this imp
ortant question.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shiraz Minwalla (TIFR)
DTSTART:20210224T093000Z
DTEND:20210224T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/55
DESCRIPTION:Title: Bounds on Regge growth of flat space scattering from bounds on
chaos\nby Shiraz Minwalla (TIFR) as part of ICTS String Seminars\n\n\
nAbstract\nWe study four-point functions of scalars\, conserved currents\,
and stress tensors in a conformal field theory\, generated by a local con
tact term in the bulk dual description\, in two different causal configura
tions. The first of these is the standard Regge configuration in which the
chaos bound applies. The second is the `causally scattering configuration
' in which the correlator develops a bulk point singularity. We find an ex
pression for the coefficient of the bulk point singularity in terms of the
bulk S matrix of the bulk dual metric\, gauge fields and scalars\, and us
e it to determine the Regge scaling of the correlator on the causally scat
tering sheet in terms of the Regge growth of this S matrix. We then demons
trate that the scaling on this this sheet is governed by the same power as
in the standard Regge configuration\, and so is constrained by the chaos
bound\, which turns out to be violated unless the bulk flat space S matrix
grows no faster than s^2\nin the Regge limit. It follows that in the cont
ext of the AdS/CFT correspondence and local bulk interactions that the ch
aos bound applied to the boundary field theory implies that the S matrices
of the dual bulk scalars\, gauge fields\, and gravitons obey the Classica
l Regge Growth (CRG) conjecture.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nava Gaddam (University of Utrecht)
DTSTART:20210303T093000Z
DTEND:20210303T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/56
DESCRIPTION:Title: The black hole eikonal and the information paradox\nby Nav
a Gaddam (University of Utrecht) as part of ICTS String Seminars\n\n\nAbst
ract\nIn this talk\, I will show that there is a remarkable phase of quant
um gravity (which we will call the 'black hole eikonal' phase in contrast
to the flat space eikonal phase). It is defined by gravitational collision
s near the horizon\, and dominated by centre of mass energies $E >> \\gamm
a M_Pl$\, with $\\gamma = M_Pl/M_B H$. This regime captures gravitational
scattering with impact parameters smaller than the Schwarzschild radius. S
cattering amplitudes are unitary suggesting a resolution of the informatio
n paradox\; I will sketch the explicit derivation of the 2-2 amplitude for
massless scalars\, non-perturbatively in $\\gamma$. Owing to the low ener
gies of collisions\, there are no firewalls experienced by infalling obser
vers. A consequence of these results is that the information paradox is an
emergent one at low energies and does not require detailed ultra-violet p
hysics for a resolution.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jaume Gomis (Perimeter Institute)
DTSTART:20210326T130000Z
DTEND:20210326T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/57
DESCRIPTION:Title: Global Anomalies on the Hilbert Space\nby Jaume Gomis (Per
imeter Institute) as part of ICTS String Seminars\n\n\nAbstract\nWe will d
iscuss an elementary way of detecting some global anomalies\nfrom the way
the symmetry algebra is realized on the torus Hilbert\nspace of the anomal
ous theory\, give a physical description of the\nimprint of the “layers
”that enter in the cobordism classification of\nanomalies and discuss ap
plications\, including how anomalies can imply\na supersymmetric spectrum
in strongly coupled (nonsupersymmetric)\ngauge theories.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Masanori Hanada (University of Surrey)
DTSTART:20210331T093000Z
DTEND:20210331T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/58
DESCRIPTION:Title: Color confinement\, Bose-Einstein condensation\, and emergent
geometry in gauge/gravity duality\nby Masanori Hanada (University of S
urrey) as part of ICTS String Seminars\n\n\nAbstract\nIn gauge/gravity dua
lity\, the information regarding the gravitational geometry (e.g.\, black
hole and smooth exterior geometry) has to be encoded in gauge theory. The
color degrees of freedom (matrix degrees of freedom) have to play the key
role\, because the duality can hold even when the gauge theory side is a m
atrix model. In this talk\, I will provide a very simple way of encoding t
he geometry to matrices\, along the line of Witten's work on the effective
action of D-branes and strings\, and the Matrix Theory conjecture by Bank
s\, Fischler\, Shenker and Susskind. Roughly speaking\, eigenvalues of mat
rices can be identified with the location of the D-brane probe or extended
objects such as black hole. \n\nActually there is a famous argument again
st such simple interpretation advocated by Polchinski in 1998. His argumen
t used generic properties of large-N gauge theory to show that the ground-
state wave function delocalizes at large N\, leading to a conflict with th
e locality in the bulk geometry. We show that this argument is not correct
: the ground-state wave function does not delocalize\, and there is no con
flict with the locality of the bulk geometry. In order to understand how P
olchinski's argument fails\, recently-discovered connection between color
confinement at large N and Bose-Einstein condensation is useful. This conf
inement-BEC connection has a striking consequence: in the SU(N) gauge theo
ry\, there is a partially-deconfined phase in which an SU(M)-subgroup is d
econfined. Partial deconfinement gives a natural realization of the idea i
n BFSS Matrix Theory conjecture --- extended objects\, such as black hole\
, are realized as bound states of D-branes and strings\, that look like no
n-commutative blocks in big matrices --- in the Maldacena-type gauge/gravi
ty duality.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikhil Kalyanapuram (Pennsylvania State University)
DTSTART:20210428T093000Z
DTEND:20210428T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/59
DESCRIPTION:Title: The Tensionless Limit of Chiral Superstring Integrands\nby
Nikhil Kalyanapuram (Pennsylvania State University) as part of ICTS Strin
g Seminars\n\n\nAbstract\nChiral splitting is the superholomorphic factori
sation of integrands in superstring theory\, derived several decades ago b
y D'Hoker and Phong. I will place this phenomenon in a modern context by e
xpanding the chiral integrand of external graviton states in terms of the
string tension. In doing so\, the half integrand of the ambitwistor string
will be shown to arise as a tensionless limit thereof. The possible impli
cations for the duality between colour and kinematics will be discussed.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aninda Sinha (IISc)
DTSTART:20210421T093000Z
DTEND:20210421T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/60
DESCRIPTION:Title: Crossing symmetric dispersion relations in QFTs and CFTs\n
by Aninda Sinha (IISc) as part of ICTS String Seminars\n\n\nAbstract\nI wi
ll discuss crossing symmetric dispersion relations and its applications. 1
) In QFT I will derive two sided bounds on Wilson coefficients in a low en
ergy effective expansion of 2-2 scattering. I will also show an intriguing
connection with the Bieberbach conjecture in mathematics. 2) In CFT\, I w
ill show a rigorous derivation of the Polyakov bootstrap which will enable
us to fix the contact terms in the Witten diagram basis expansion.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Congkao Wen (Queen Mary University)
DTSTART:20210407T093000Z
DTEND:20210407T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/61
DESCRIPTION:Title: Integrated four-point correlators in N=4 SYM\nby Congkao W
en (Queen Mary University) as part of ICTS String Seminars\n\n\nAbstract\n
In this talk\, we will discuss integrated correlators of four superconform
al primaries in N=4 super Yang-Mills\, that are defined by integrating ove
r spacetime coordinates of the four-point correlator with certain integrat
ion measures. The integrated correlators can be computed using supersymmet
ric localisation\, which are expressed as N-dimensional matrix-model integ
rals. We will mostly focus on one of the integrated correlators. We find t
hat this integrated correlator can be presented as a lattice sum\, which m
akes manifest the SL(2\, Z) modular invariance of N=4 SYM. Furthermore\,
the integrated correlator obeys a remarkable Laplace-difference equation\,
which relates the correlator of SU(N) theory with those of SU(N-1) and SU
(N+1) theories. The expression allows us to obtain exact results of the i
ntegrated correlator in various limits. For instance\, in perturbation\, t
he expression is checked to be consistent with known results in the litera
ture\; in the large-N limit\, it is shown to match with the expected resul
ts from string theory due to AdS/CFT duality.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chethan Krishnan (IISc)
DTSTART:20210505T093000Z
DTEND:20210505T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/62
DESCRIPTION:Title: Comments on the Information Paradox\nby Chethan Krishnan (
IISc) as part of ICTS String Seminars\n\n\nAbstract\nI will discuss some c
alculations that shed light on some of the conceptual questions regarding
(recent developments on) the information paradox.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/62/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Biswajit Sahoo (EPFL)
DTSTART:20210602T093000Z
DTEND:20210602T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/63
DESCRIPTION:Title: Classical Soft Graviton Theorem and Gravitational Memory\n
by Biswajit Sahoo (EPFL) as part of ICTS String Seminars\n\n\nAbstract\nFi
rst I shall briefly review the results of the quantum soft graviton theore
m derived from scattering amplitudes. Then I briefly discuss the classical
limit of the soft graviton theorem to show how it is related to the long-
wavelength gravitational waveform. Finally\, I shall talk about the deriva
tion of the classical soft graviton theorem in detail and how it is relate
d to gravitational memory. I shall also address the following questions al
ong with some observational signature:\n\nHow to derive all order soft the
orem and gravitational memory systematically\, and how much have we succee
ded?\n\nIn which order of soft expansion spin and structure of the scatter
ed objects start contributing?\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Subir Sachdev (Harvard)
DTSTART:20210609T130000Z
DTEND:20210609T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/64
DESCRIPTION:Title: Random t-J model theory of the cuprate phase diagram\nby S
ubir Sachdev (Harvard) as part of ICTS String Seminars\n\n\nAbstract\nThe
cuprate high temperature superconductors display three distinct metallic p
hases around the superconducting dome: a pseudogap metal at low doping\, a
n intermediate Planckian metal\, and a Fermi liquid at large doping. I wil
l present numerical and analytical results showing that all three phases a
re present in the t-J model with random and all-to-all hopping and exchang
e. The Planckian metal is realized in a SYK-type theory of fractionalized
holons and spinons: it exhibits linear-in-temperature resistivity at low t
emperatures (in a closely-related large-dimension model) arising from a ti
me reparameterization soft mode. This soft mode has a holographic interpr
etation as a boundary graviton of charged black holes.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kristan Jensen (Victoria)
DTSTART:20210512T050000Z
DTEND:20210512T060000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/65
DESCRIPTION:Title: Wormholes and black hole microstates in AdS/CFT\nby Krista
n Jensen (Victoria) as part of ICTS String Seminars\n\n\nAbstract\nIt has
long been known that the coarse-grained approximation to the black hole de
nsity of states can be computed using classical Euclidean gravity. In this
talk I will argue for another entry in the dictionary between Euclidean g
ravity and black hole physics\, namely that Euclidean wormholes describe a
coarse-grained approximation to the energy level statistics of black hole
microstates. We obtain an integral representation of wormhole amplitudes
in Einstein gravity and in full-fledged AdS/CFT. These amplitudes are non-
perturbative corrections to the two-boundary problem in AdS quantum gravit
y. The full amplitude is likely UV sensitive\, dominated by small wormhole
s\, but it admits an integral transformation with a macroscopic\, weakly c
urved saddle-point approximation. The saddle is the "double cone" geometry
of Saad\, Shenker\, and Stanford\, with fixed moduli. In the boundary des
cription this saddle appears to dominate a smeared version of the connecte
d two-point function of the black hole density of states\, and suggests le
vel repulsion in the microstate spectrum. I will also discuss the stabilit
y of these wormholes to small fluctuations and to brane nucleation. Our re
sults indicate a factorization paradox in AdS/CFT.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Poland (Yale)
DTSTART:20210520T130000Z
DTEND:20210520T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/66
DESCRIPTION:Title: Charting the Landscape of 3d CFTs\nby David Poland (Yale)
as part of ICTS String Seminars\n\n\nAbstract\nI will summarize progress a
t using the conformal bootstrap to solve 3d CFTs. These include the critic
al 3d Ising model\, the O(N) vector models\, and the minimal 3d SCFT. Rece
nt results for the O(2) model resolve a longstanding discrepancy between e
xperiment and Monte Carlo simulations\, while results for the O(3) model p
rove the instability of Heisenberg magnets to cubic anisotropy.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/66/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthew Reece (Harvard)
DTSTART:20210527T130000Z
DTEND:20210527T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/67
DESCRIPTION:Title: No Global Symmetries\, with Applications to Axions and Cosmic
Strings\nby Matthew Reece (Harvard) as part of ICTS String Seminars\n\
n\nAbstract\nThere are reasons to believe that consistent quantum gravity
theories do not admit exact global symmetries. This claim has surprisingly
strong implications\, some of which are relevant for particle physics and
cosmology. I will discuss some recent variations on this theme\, includin
g the absence of Chern-Weil symmetries (with applications to axion physics
) and the absence of higher-form symmetries (with implications for the exi
stence of cosmic strings).\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stephane Detournay (Brussels U.)
DTSTART:20210616T093000Z
DTEND:20210616T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/68
DESCRIPTION:Title: The 3d black string and its dual\nby Stephane Detournay (B
russels U.) as part of ICTS String Seminars\n\n\nAbstract\nAbout 30 years
ago\, Horne and Horowitz described a three-dimensional black string soluti
on sharing many qualitative features of the Reissner-Nordstrom black hole.
\nViewing the black string as a certain deformation of the BTZ black hole\
, we will give evidence that its field theory dual consists in an irreleva
nt deformation of a 2d CFT of the TTbar form.\nBased on 1911.12359 with L
uis Apolo and Wei Song.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Soumangsu Chakraborty (TIFR)
DTSTART:20210707T093000Z
DTEND:20210707T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/69
DESCRIPTION:Title: (SL(2\,R) X U(1))/U(1) CFT\, NS5+F1 system & single trace TTba
r\nby Soumangsu Chakraborty (TIFR) as part of ICTS String Seminars\n\n
\nAbstract\nIn this talk\, I'm going to talk about the equivalence among (
i) the weakly coupled worldsheet string theory described by the coset sigm
a model $\\frac{SL(2\,\\mathbb{R})_k\\times U(1)}{U(1)}\\times S^3 \\times
T^4$ with $SL(2\,\\mathbb{R})$ WZW level $k\\geq 2$\, (ii) the full near
horizon theory of the NS5 branes with $k$ NS5 branes wrapping $T^4\\times
S^1$\, $p\\gg1$ F1 strings wrapping $S^1$ and $n$ units of momentum along
the $S^1$ and (iii) the single trace $T\\bar{T}$ deformation of string the
ory in $AdS_3\\times S^3\\times T^4$. As a check\, I'll compute the spect
rum of the spacetime theory by performing BRST quantization of the coset d
escription of the worldsheet theory and show that it matches exactly with
the one derived in the case of single trace $T\\bar{T}$ deformed string th
eory in $AdS_3$. If time permits\, I'll talk about the two-point function
of the spacetime theory.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/69/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Felix Haehl (IAS)
DTSTART:20210714T130000Z
DTEND:20210714T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/71
DESCRIPTION:Title: The p-spin glass model: a holographer's point of view\nby
Felix Haehl (IAS) as part of ICTS String Seminars\n\n\nAbstract\nI will di
scuss a large-N bosonic quantum mechanical sigma-model with a spherical ta
rget space subject to disordered interactions\, more colloquially known as
the p-spin spherical model. Replica symmetry is broken at low temperature
s and for sufficiently weak quantum fluctuations\, which drives the system
into a spin glass phase. This spin glass phase exhibits an emergent confo
rmal symmetry in the strong coupling regime\, which dictates its thermodyn
amic properties. I will discuss an approximate analytical solution to the
spin glass equations\, which interpolates between the conformal regime and
a consistent short-distance solution. I will also discuss the real-time d
ynamics of the model with emphasis on quantum chaos as measured by out-of-
time-order four-point functions. We find exponential Lyapunov growth\, whi
ch intricately depends on the model's couplings. The spin glass phase also
exhibits quantum chaos\, albeit with parametrically smaller Lyapunov expo
nent than in the replica symmetric phase. An analytical calculation in the
spin glass phase suggests that this Lyapunov exponent vanishes in a parti
cular infinite coupling limit. I will comment on the potential meaning of
these observations from the perspective of holography.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/71/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anindya Dey (Johns Hopkins)
DTSTART:20210804T130000Z
DTEND:20210804T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/73
DESCRIPTION:Title: S-type Operations\, Line Defects and 3D Mirror Symmetry beyond
ADE quivers\nby Anindya Dey (Johns Hopkins) as part of ICTS String Se
minars\n\n\nAbstract\nI will present a systematic field theory prescriptio
n for constructing 3D N=4 mirror pairs involving quiver gauge theories bey
ond the well-known ADE examples. The construction involves a certain gener
alization of the S operation\, which arises in the context of the 3d SL(2\
,Z) action on a CFT with a U(1) 0-form symmetry. I will show how this cons
truction can be used to determine 3d Lagrangians for a large class of Argy
res-Douglas theories compactified on a circle. I will also discuss how the
prescription can be extended to include half-BPS line defects and determi
ne the associated mirror maps\, which were only known earlier for A-type t
heories.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/73/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Suresh Govindarajan (IIT Madras)
DTSTART:20210728T093000Z
DTEND:20210728T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/74
DESCRIPTION:Title: Looking for a new kind of Lie algebra using a clue from counti
ng dyon degeneracies\nby Suresh Govindarajan (IIT Madras) as part of I
CTS String Seminars\n\n\nAbstract\nThe refined counting of BPS states in f
our-dimensional string\ntheories with $N=4$ supersymmetry has brought inte
resting connections with\nmodular forms\, mock modular forms\, Lie algebra
s and the surprising\nappearance of the sporadic simple group\, $M_24$\, i
s called Mathieu\nmoonshine. The (inverse of the) generating function of d
yon degeneracies\nis a Siegel modular form.\n\nIn this talk\, we focus on
the appearance of families of Lie Algebras\nthat are obtained by interpret
ing the square-root of the generating\nfunction of dyons degeneracies as t
he denominator formulae of the Lie\nalgebras. In most of the examples\, th
e Lie algebras are generalized\nKac-Moody Lie superalgebras or Borcherds-K
ac-Moody Lie superalgebras.\nThere are examples that are not BKM Lie super
algebras. In these cases\nthe square-root provides us a tool to look for a
n extension of BKM Lie\nsuperalgebras. With this in mind\, we discuss the
decomposition of this\nsquare-root in terms of an affine Lie algebra. This
leads to the\nappearance of vector valued modular forms that encode the m
ultiplicities\nof simple roots of the (potential) Lie superalgebra.\n\nBas
ed on arXiv:2106.01605\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/74/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gui Pimentel (University of Amsterdam)
DTSTART:20210929T093000Z
DTEND:20210929T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/75
DESCRIPTION:Title: Decoding and bootstrapping cosmological fluctuations\nby G
ui Pimentel (University of Amsterdam) as part of ICTS String Seminars\n\n\
nAbstract\nI will review our current understanding of the initial conditio
ns of the universe\, and describe what information is available from curre
nt and future measurements of cosmological correlation functions. Then I w
ill describe a new method to compute and constrain the possible shapes of
those correlation functions\, assuming they were generated during inflatio
n. This ``cosmological bootstrap” draws inspiration from the modern scat
tering amplitudes program in flat space\, as well as the conformal bootstr
ap of phase transitions. After discussing primordial scalar fluctuations\,
I will also explain how the consistent propagation of gravitational waves
imposes further constraints on the structure of spinning primordial corre
lators. Finally if there’s time I’ll discuss some work in progress try
ing to understand the general structure of tree level correlators in FLRW
cosmology.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/75/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alok Laddha (Chennai Mathematical Institute)
DTSTART:20211006T093000Z
DTEND:20211006T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/76
DESCRIPTION:Title: Towards a Positive Geometry for the massive S-matrix\nby A
lok Laddha (Chennai Mathematical Institute) as part of ICTS String Seminar
s\n\n\nAbstract\nS-matrix of Quantum field theory has an intricate Analyti
c structure. In the last few years\, there has been a striking development
in defining the S-matrix of scalar quantum field theories as volume of c
ertain polytopes known as Accordiohedra. These polytopes live in the kinem
atic space parametrized by Mandelstam invariants and many of the fundamen
tal properties of the S-matrix such as locality and unitarity emerge fr
om simple combinatorial properties of such polytopes. \n\nIn this talk\, w
e will review some recent ideas to extend the positive geometry program to
multi-scalar field amplitudes with scalar fields having distinct masses.
In particular\, we will analyze scattering involving two scalars with uneq
ual masses and find the class of polytopes whose volume generates S-matrix
for such theories. We will also argue that ``integrating out the heavier
field" induces a map between different accordiohedra\, thus giving some p
reliminary insight into geometrisation of effective field theory.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/76/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Evita Verheijden (University of Amsterdam)
DTSTART:20211013T093000Z
DTEND:20211013T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/77
DESCRIPTION:Title: No Page curves for the de Sitter horizon\nby Evita Verheij
den (University of Amsterdam) as part of ICTS String Seminars\n\n\nAbstrac
t\nOne of the greatest puzzles in our universe\, which can -- to good appr
oximation -- be described by de Sitter space\, is a proper understanding o
f the cosmological horizon that surrounds any observer. Over the past few
years\, a semi-classical approach involving quantum extremal surfaces and
so-called ‘islands’ has been very successful to increase our understan
ding of the black hole information problem\; in light of these advancement
s\, it could prove fruitful to undertake a similar approach to investigate
an evaporating de Sitter horizon. In this talk I will consider such an ap
proach for two-dimensional de Sitter space. Starting from three-dimensiona
l de Sitter space\, I will show how a partial dimensional reduction suppli
es 2D JT de Sitter with an auxiliary system acting as a heat bath. I will
then contrast the time-dependent entropy of radiation collected by an obse
rver at future infinity with that collected by an observer inside the stat
ic patch. Central to the analysis in the static patch is the identificatio
n of a weakly-coupled region close to the cosmological horizon. I will hig
hlight how backreaction considerations crucially obstruct both observers f
rom witnessing unitary evaporation.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/77/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Miranda Cheng (University of Amsterdam)
DTSTART:20211027T093000Z
DTEND:20211027T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/78
DESCRIPTION:Title: Machine learning and theoretical physics: some applications\nby Miranda Cheng (University of Amsterdam) as part of ICTS String Semin
ars\n\n\nAbstract\nIn this talk I will briefly summarise my two recent pap
ers on the interactions between physics and machine learning. In the paper
with V Anagiannis\, we exploit the analogy between quantum many-body syst
ems and certain neural networks to analyse the learning process using quan
tum entanglement. In the second paper with de Haan\, Rainone\, and Bondes
an\, we use a continuous flow model to help ameliorate the numerical diffi
culties in sampling in lattice field theories\, which for instance hampers
high-precision computations in LQCD.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/78/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eran Palti (Ben Gurion University)
DTSTART:20210922T093000Z
DTEND:20210922T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/79
DESCRIPTION:Title: Convexity of Charged Operators in CFTs and the Weak Gravity Co
njecture\nby Eran Palti (Ben Gurion University) as part of ICTS String
Seminars\n\n\nAbstract\nIn this talk I will introduce a particular formul
ation of the Weak Gravity Conjecture in AdS space in terms of the self-bin
ding energy of a particle. The holographic CFT dual of this formulation co
rresponds to a certain convex-like structure for operators charged under c
ontinuous global symmetries. Motivated by this\, we propose a conjecture t
hat this convexity is a general property of all CFTs\, not just those with
weakly-curved gravitational duals. It is possible to test this in simple
CFTs\, the conjecture passes all the tests performed so far.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/79/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ofer Aharony (Weizmann Institute)
DTSTART:20211019T083000Z
DTEND:20211019T093000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/80
DESCRIPTION:Title: A derivation of AdS/CFT for vector models\nby Ofer Aharony
(Weizmann Institute) as part of ICTS String Seminars\n\n\nAbstract\nAfter
discussing what it means to derive the AdS/CFT correspondence\, I will de
scribe our attempts (in collaboration with Shai Chester and Erez Urbach\,
2011.06328+2109.05512) to make this correspondence explicit in the simples
t case of the U(N) vector model\, conjectured to be dual to high-spin grav
ity in Anti-de Sitter space. We explicitly rewrite the path integral for t
he free or critical U(N) (or O(N)) bosonic vector models in d space-time d
imensions as a path integral over fields (including massless high-spin fie
lds) living on (d+1)-dimensional anti-de Sitter space. Inspired by de Mell
o Koch\, Jevicki\, Suzuki and Yoon and earlier work\, we first rewrite the
vector models in terms of bi-local fields\, then expand these fields in e
igenmodes of the conformal group\, and finally map these eigenmodes to tho
se of fields on anti-de Sitter space. Our results provide an explicit (non
-local) action for a high-spin theory on anti-de Sitter space\, which is p
resumably equivalent in the large N limit to Vasiliev's classical high-spi
n gravity theory (with some specific gauge-fixing to a fixed background)\,
but which can be used also for loop computations. Our mapping is explicit
within the 1/N expansion\, but in principle can be extended also to finit
e N theories\, where extra constraints on products of bulk fields need to
be taken into account.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/80/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lorenz Eberhardt (IAS)
DTSTART:20211103T120000Z
DTEND:20211103T130000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/81
DESCRIPTION:Title: A perturbative CFT dual for pure NS-NS AdS3 strings\nby Lo
renz Eberhardt (IAS) as part of ICTS String Seminars\n\n\nAbstract\nI will
discuss perturbative string theory on AdS3 with pure NS-NS flux and propo
se a dual spacetime CFT. It is given by a symmetric orbifold of a linear d
ilaton theory deformed by a marginal operator from the twist-2 sector. I e
xplain the computation of two- and three-point functions on the CFT side t
o 4th order in conformal perturbation theory at large N. They agree with t
he string computation at genus 0\, thus providing ample evidence for a dua
lity. I also explain how to match the full spectra of both short and long
strings.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/81/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexandre Belin (CERN)
DTSTART:20211110T093000Z
DTEND:20211110T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/82
DESCRIPTION:Title: Quantum Gravity meets Statistical Physics\nby Alexandre Be
lin (CERN) as part of ICTS String Seminars\n\n\nAbstract\nIn this talk\, I
will discuss the statistical distribution of OPE coefficients in chaotic
conformal field theories. I will present the OPE Randomness Hypothesis (OR
H)\, a generalization of ETH to CFTs which treats any OPE coefficient invo
lving a heavy operator as a pseudo-random variable with an approximate Gau
ssian distribution. I will then present some evidence for this conjecture\
, based on the size of the non-Gaussianities and on insights from random m
atrix theory. Turning to the bulk\, I will argue that semi-classical gravi
ty geometrizes these statistical correlations by wormhole geometries. I wi
ll show that the non-Gaussianities of the OPE coefficients predict a new c
onnected wormhole geometry that dominates over the genus-2 wormhole.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/82/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Monica Guica (IPhT)
DTSTART:20211124T093000Z
DTEND:20211124T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/83
DESCRIPTION:Title: JTbar-deformed CFTs as non-local CFTs\nby Monica Guica (IP
hT) as part of ICTS String Seminars\n\n\nAbstract\nVarious holographic set
-ups in string theory suggest the existence of non-local\, UV complete two
-dimensional QFTs that possess Virasoro symmetry\, in spite of their non-l
ocality. We argue that JTbar-deformed CFTs are the first concrete realisat
ion of such "non-local CFTs"\, through a detailed analysis of their classi
cal and quantum symmetry algebra. Concretely\, we show that JTbar-deformed
CFTs possess an infinite set of symmetries\, which in a certain basis or
ganise into two commuting copies of the Virasoro-Kac-Moody algebra\, with
the same central extension as that of the undeformed CFT. A peculiarity of
these Virasoro generators is that their zero mode does not equal the Hami
ltonian\, but is a quadratic function of it\; this helps reconcile the Vir
asoro symmetry with the non-locality of the model. We argue that TTbar-de
formed CFTs also possess Virasoro symmetries of this type.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/83/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nissan Itzhaki (Tel Aviv University)
DTSTART:20211201T093000Z
DTEND:20211201T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/84
DESCRIPTION:Title: A Puncture in the Euclidean Black Hole\nby Nissan Itzhaki
(Tel Aviv University) as part of ICTS String Seminars\n\n\nAbstract\nWe co
nsider the backreaction of the winding zero mode on the cigar geometry. We
focus on the case of the $SL(2\,R)_k/U(1)$ cigar associated with e.g. the
near-horizon limit of $k$ NS5 black-branes. We solve the equations of mot
ion numerically in the large $k$ limit as a function of the amplitude of t
he winding mode at infinity. We find that there is a critical amplitude $C
_c=\\exp(-\\gamma/2)$ that admits a critical solution. The exact CFT descr
iption of the $SL(2\,R)_k/U(1)$ cigar\, in particular the FZZ duality\, fi
xes completely the winding amplitude. We find that in the large $k$ limit
there is an exact agreement $C_c=C_{FZZ}$. The critical solution is a ciga
r with a puncture at its tip\; consequently\, the BH entropy is carried en
tirely by the winding condensate. We argue that\, in the Lorentzian case\,
the information is ejected from the black hole through this puncture.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/84/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Maldacena (IAS)
DTSTART:20211117T120000Z
DTEND:20211117T130000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/85
DESCRIPTION:Title: On the black hole/string transition\nby Juan Maldacena (IA
S) as part of ICTS String Seminars\n\n\nAbstract\nWe discuss aspects of th
e possible transition between small black holes and highly excited fundame
ntal strings. We focus on the connection between black holes and the self
gravitating string solution of Horowitz and Polchinski. This solution is i
nteresting because it has non-zero entropy at the classical level and it i
s natural to suspect that it might be continuously connected to the black
hole. Surprisingly\, we find a different behavior for heterotic and type I
I cases. For the type II case we find an obstruction to the idea that the
two are connected as classical solutions of string theory\, while no such
obstruction exists for the heterotic case. We further provide a linear sig
ma model analysis that suggests a continuous connection for the heterotic
case. We also describe a solution generating transformation that produces
a charged version of the self gravitating string. This provides a fuzzball
-like construction of near extremal configurations carrying fundamental st
ring momentum and winding charges. We provide formulas which are exact in
α′ relating the thermodynamic properties of the charged and the uncharg
ed solutions.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/85/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shamik Banerjee (IOP Bhubaneswar)
DTSTART:20211208T093000Z
DTEND:20211208T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/86
DESCRIPTION:Title: MHV graviton scattering amplitudes from celestial current alge
bras\nby Shamik Banerjee (IOP Bhubaneswar) as part of ICTS String Semi
nars\n\n\nAbstract\nIn this talk I will describe how one can determine the
MHV graviton scattering amplitudes from celestial current algebras. I wil
l also discuss recent developments in our understanding of the symmetries
of general tree level graviton scattering amplitudes in Einstein gravity.\
n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/86/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sourav Roychowdhury (CMI Chennai)
DTSTART:20211222T093000Z
DTEND:20211222T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/89
DESCRIPTION:Title: Non-Abelian T-dual of Klebanov-Tseytlin background and its Pen
rose limits\nby Sourav Roychowdhury (CMI Chennai) as part of ICTS Stri
ng Seminars\n\n\nAbstract\nIn this talk I will discuss Klebanov-Tseytlin b
ackground and it’s non-Abelian T-dual geometry. In particular I will sho
w that the T-dual background admits pp-wave geometry in the neighbourhood
of appropriate null geodesic. I will make comments on possible dual gauge
theory\nfor our pp-wave background.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/89/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dalimil Mazac (IAS)
DTSTART:20220202T050000Z
DTEND:20220202T060000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/90
DESCRIPTION:Title: Automorphic Spectra and the Conformal Bootstrap\nby Dalimi
l Mazac (IAS) as part of ICTS String Seminars\n\n\nAbstract\nI will explai
n that the spectral geometry of hyperbolic manifolds provides a remarkably
faithful model of the modern conformal bootstrap. In particular\, to each
hyperbolic D-manifold\, one can associate a Hilbert space of local operat
ors\, which is a unitary representation of a conformal group. The local op
erators live in an emergent (D-1)-dimensional spacetime. The scaling dimen
sions of the operators are related to the eigenvalues of the Laplacian on
the manifold. The operators satisfy an operator product expansion. Finally
\, one can define their correlation functions and derive bootstrap equatio
ns constraining the spectrum. As an application\, I will use conformal boo
tstrap techniques to derive upper bounds on the lowest positive eigenvalue
of the Laplacian on closed hyperbolic surfaces and 2-orbifolds. In a numb
er of notable cases\, the bounds are nearly saturated by known surfaces an
d orbifolds. For instance\, the bound on all genus-2 surfaces is λ1≤3.8
388976481\, while the Bolza surface has λ1≈3.838887258. The talk will b
e based on https://arxiv.org/abs/2111.12716\, which is joint work with P.
Kravchuk and S. Pal.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/90/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arjun Bagchi (IIT Kanpur)
DTSTART:20220216T093000Z
DTEND:20220216T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/91
DESCRIPTION:Title: Tensionless Tales\nby Arjun Bagchi (IIT Kanpur) as part of
ICTS String Seminars\n\n\nAbstract\nThe tensionless limit of string theor
y has long been an enigmatic regime of the theory. In this talk\, I give a
n overview of the recent developments in understanding tensionless bosonic
closed strings in flat space based on the symmetries on the worldsheet wh
ich turn out to be the Bondi-Metzner-Sachs (BMS) algebra. After a broad in
troduction\, I will touch upon various new developments\, including a clos
ed-to-open string transition\, different tensionless vacua\, and Rindler p
hysics appearing on the worldsheet.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/91/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shahin Sheikh-Jabbari (IPM Tehran)
DTSTART:20220105T093000Z
DTEND:20220105T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/92
DESCRIPTION:Title: Null Surface Thermodynamics\nby Shahin Sheikh-Jabbari (IPM
Tehran) as part of ICTS String Seminars\n\n\nAbstract\nWe study D dimensi
onal pure Einstein gravity theory in a region of spacetime bounded by a ge
neric null boundary. We show besides the graviton modes propagating in the
bulk\, the system is described by boundary degrees of freedom labeled by
D surface charges associated with nontrivial diffeomorphisms at the bounda
ry. We establish that the system admits a natural thermodynamical descript
ion. Using standard surface charge analysis and covariant phase space meth
od\, we formulate laws of null surface thermodynamics which are local equa
tions over an arbitrary null surface. This thermodynamical system is gener
ally an open system and can be closed only when there is no flux of gravit
ons through the null surface. Our analysis extends the usual black hole th
ermodynamics to a universal feature of any area element on a generic null
surface.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/92/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shreya Vardhan (MIT)
DTSTART:20220209T130000Z
DTEND:20220209T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/93
DESCRIPTION:Title: Mixed-state entanglement and information recovery in evaporati
ng black holes\nby Shreya Vardhan (MIT) as part of ICTS String Seminar
s\n\n\nAbstract\nIt is generally expected that during the black hole evapo
ration process\, correlations within the Hawking radiation first start to
grow at a time scale called the Page time. The information of a diary thro
wn into the black hole is also expected to become accessible from the radi
ation at the Page time. These expectations are based on averages over Haar
-random pure states\, which assume that the evaporating black hole resembl
es an equilibrated pure state at infinite temperature. Using a method call
ed the equilibrium approximation\, we study the universal behavior of quan
tities such as logarithmic negativity and Petz map fidelity in equilibrate
d pure states at finite temperature. This reveals surprising new features
of the entanglement structure of the black hole and its radiation in the p
resence of energy constraints. In particular\, we find that both the entan
glement within the radiation and the likelihood of information recovery fi
rst start to grow at a new time scale\, which is earlier than the Page tim
e by a finite fraction of the total evaporation time.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/93/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hong Liu (MIT)
DTSTART:20220223T033000Z
DTEND:20220223T043000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/94
DESCRIPTION:Title: Emergent times in holography\nby Hong Liu (MIT) as part of
ICTS String Seminars\n\n\nAbstract\nIn holographic duality an eternal AdS
black hole is described by two copies of the boundary CFT in the thermal
field double state. We provide explicit constructions in the boundary theo
ry of infalling time evolutions which can take bulk observers behind the h
orizon. The constructions also help to illuminate the boundary emergence o
f the black hole horizons\, the interiors\, and the associated causal stru
cture. A key element is the emergence\, in the large N limit of the bounda
ry theory\, of a type III1 von Neumann algebraic structure and the half-si
ded modular translation structure associated with it.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/94/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eric Sharpe (Virginia Tech)
DTSTART:20220302T133000Z
DTEND:20220302T143000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/95
DESCRIPTION:Title: An introduction to decomposition\nby Eric Sharpe (Virginia
Tech) as part of ICTS String Seminars\n\n\nAbstract\nIn this talk I will
review work on `decomposition\,' a property of 2d theories with 1-form sym
metries and\, more generally\, d-dim'l theories with (d-1)-form symmetries
. Decomposition is the observation that such quantum field theories are
equivalent to ('decompose into’) disjoint unions of other QFTs\, known i
n this context as "universes.” Examples include two-dimensional gauge th
eories and orbifolds with matter invariant under a subgroup of the gauge g
roup. Decomposition explains and relates several physical properties of th
ese theories -- for example\, restrictions on allowed instantons arise as
a "multiverse interference effect" between contributions from constituent
universes. First worked out in 2006 as part of efforts to understand strin
g propagation on stacks\, decomposition has been the driver of a number of
developments since. In the first half of this talk\, I will review decomp
osition\; in the second half\, I will focus on the recent application to a
nomaly resolution of Wang-Wen-Witten in two-dimensional orbifolds.\n\nTalk
joint with the Math-Pays seminar series (https://researchseminars.org/sem
inar/ictsmathphys).\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/95/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eric Perlmutter (IPhT (Saclay))
DTSTART:20220316T093000Z
DTEND:20220316T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/96
DESCRIPTION:Title: Harnessing S-Duality in N=4 SYM & Supergravity as SL(2\,Z)-Ave
raged Strings\nby Eric Perlmutter (IPhT (Saclay)) as part of ICTS Stri
ng Seminars\n\n\nAbstract\nI will talk about this paper\, written with Sco
tt Collier: https://arxiv.org/abs/2201.05093\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/96/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tim Adamo (University of Edinburgh)
DTSTART:20220309T093000Z
DTEND:20220309T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/97
DESCRIPTION:Title: Twistor theory and infinite-dimensional soft symmetries\nb
y Tim Adamo (University of Edinburgh) as part of ICTS String Seminars\n\n\
nAbstract\nRecently\, certain infinite towers of soft theorems associated
with the self-dual sector of gravity were discovered by recasting scatteri
ng amplitudes in a conformal primary basis. The generators of the soft the
orems miraculously organize themselves into a certain infinite-dimensional
algebra which arises in 2d CFTs. I will discuss how this miracle is almos
t tautological from the perspective of twistor theory\, which enables a fi
rst-principles derivation of many of recent results in celestial holograph
y.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/97/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edward Witten (IAS\, Princeton)
DTSTART:20220301T130000Z
DTEND:20220301T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/98
DESCRIPTION:Title: No Ensemble Averaging Below the Black Hole Threshold\nby E
dward Witten (IAS\, Princeton) as part of ICTS String Seminars\n\nAbstract
: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/98/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chris Akers (MIT)
DTSTART:20220323T130000Z
DTEND:20220323T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/99
DESCRIPTION:Title: Black holes as non-isometric codes\nby Chris Akers (MIT) a
s part of ICTS String Seminars\n\n\nAbstract\nThe interior of an old black
hole is encoded in the Hawking radiation. This seems to be the implicatio
n of recent computations of the Page curve. We take this idea to its logic
al conclusion\, modeling old black holes as quantum codes embedding a larg
e number of degrees of freedom (the interior and semiclassical radiation)
into a smaller number (the stretched horizon and physical radiation). I wi
ll prove that such codes exist\, and explain their novel properties and wh
at they can tell us about black holes. \n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/99/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shu-Heng Shao (Stony Brook)
DTSTART:20220401T133000Z
DTEND:20220401T143000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/100
DESCRIPTION:Title: Non-invertible symmetries from higher gauging\nby Shu-Hen
g Shao (Stony Brook) as part of ICTS String Seminars\n\n\nAbstract\nWe dis
cuss invertible and non-invertible topological defects arising from gaugin
g a discrete higher-form symmetry on a higher codimensional manifold in sp
acetime\, which we define as higher gauging. A higher-form symmetry is cal
led p-gaugeable if it can be gauged on a codimension-p manifold in spaceti
me. We focus on 1-gaugeable 1-form symmetries in general 2+1d QFT\, and ga
uge them on a surface in spacetime. The universal fusion rules of the resu
lting invertible and non-invertible condensation surfaces are determined.
In the special case of 2+1d TQFT\, every ordinary global symmetry is reali
zed from higher gauging. We further determine the fusion rules be- tween t
he surfaces\, lines\, and lines that only live on the surfaces\, making th
e first step towards building a fusion 2-category. We emphasize that the f
usion “coefficients” in these non-invertible fusion rules are generall
y not numbers\, but 1+1d TQFTs. Finally\, we discuss examples of non-inver
tible symmetries in non-topological QFT such as the free compact scalar th
eory and QED.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/100/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sabrina Pasterski (Perimeter Institute)
DTSTART:20220420T123000Z
DTEND:20220420T133000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/102
DESCRIPTION:Title: Revisiting the Flat Space Hologram\nby Sabrina Pasterski
(Perimeter Institute) as part of ICTS String Seminars\n\n\nAbstract\nWe st
art by revisiting the task of constructing a holographic dual to quantum g
ravity in asymptotically flat spacetimes. Upon recasting the S-matrix in t
erms of data at the conformal boundary\, we see that the two standard appr
oaches (Carrollian and Celestial) amount to slicing up the bulk and bounda
ry in different ways. In particular\, the Celestial Hologram organizes sca
ttering from the point of view of Rindler evolution. \n\nNow the main moti
vation for Celestial Holography comes from the connection between soft the
orems and asymptotic symmetries in asymptotically flat spacetimes\, and ou
r ability to recast soft operators as currents in a codimension 2 CFT. Tak
ing radial = Rindler evolution provides a streamlined route from asymptot
ic symmetries in 4D asymptotically flat spacetimes to currents in a 2D cel
estial CFT in a manner that makes their relation to QFT soft theorems mani
fest. We use this to reconcile the construction of charges in CCFT with th
e more familiar construction from AdS/CFT\, despite the differing codimens
ion\, and discuss the advantages of the celestial basis.\n\nBased on 2201.
06805 and 2202.11127\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/102/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kevin Costello (Perimeter Institute)
DTSTART:20220427T130000Z
DTEND:20220427T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/103
DESCRIPTION:Title: On the associativity of one loop corrections to the celestial
OPE\nby Kevin Costello (Perimeter Institute) as part of ICTS String S
eminars\n\n\nAbstract\nThe celestial holography program suggests that coll
inear singularities in gauge theory and gravity can form the OPE coefficie
nts of a two-dimensional CFT. We investigate whether known one-loop correc
tions to QCD collinear singularities satisfy the associativity conditions
of an OPE. We find they do not\, but that associativity can be restored f
or certain gauge groups by a certain Green-Schwarz mechanism. This is join
t work with Natalie Paquette.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/103/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuji Tachikawa (IPMU)
DTSTART:20220525T060000Z
DTEND:20220525T070000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/104
DESCRIPTION:Title: Undecidable problems in quantum field theory\nby Yuji Tac
hikawa (IPMU) as part of ICTS String Seminars\n\n\nAbstract\nWe point out
that some questions in quantum field theory are undecidable in a precise m
athematical sense. More concretely\, it will be demonstrated that there is
no algorithm answering whether a given 2d supersymmetric Lagrangian theor
y breaks supersymmetry or not. It will also be shown that there is a speci
fic 2d supersymmetric Lagrangian theory which breaks supersymmetry if and
only if the standard Zermelo-Fraenkel set theory with the axiom of choice
is consistent\, which can never be proved or disproved as the consequence
of Gödel's second incompleteness theorem. The article includes a brief an
d informal introduction to the phenomenon of undecidability and its previo
us appearances in theoretical physics. This talk is based on 2203.16689 .\
n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/104/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sunil Sake (TIFR)
DTSTART:20220413T093000Z
DTEND:20220413T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/105
DESCRIPTION:by Sunil Sake (TIFR) as part of ICTS String Seminars\n\nAbstra
ct: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/105/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edgar Shaghoulian (University of Pennsylvania)
DTSTART:20220511T133000Z
DTEND:20220511T143000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/106
DESCRIPTION:Title: The central dogma and entanglement in de Sitter space\nby
Edgar Shaghoulian (University of Pennsylvania) as part of ICTS String Sem
inars\n\n\nAbstract\nThe central dogma of black hole physics – which say
s that from the outside a black hole can be described in terms of a quantu
m system with exp(Area/4G) states evolving unitarily – has recently been
supported by computations indicating that the interior of the black hole
is encoded in the Hawking radiation of the exterior. In this paper\, we pr
obe whether such a dogma for cosmological horizons has any support from si
milar computations.The fact that the de Sitter bifurcation surface is a mi
nimax surface (instead of a maximin surface in the case of black holes) ca
uses problems with this interpretation when trying to import calculations
analogous to the AdS case. This suggests placing the holographic dual on t
he de Sitter horizon itself\, where we formulate a two-sided extremization
prescription for computing entanglement entropy in the holographic dual.
We find answers consistent with general expectations for a quantum theory
of de Sitter space\, including a vanishing total entropy and an entropy of
A/4G when restricting to a single static patch. We will also explore some
of its more exotic predictions.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/106/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dam Thanh Son (University of Chicago)
DTSTART:20220504T130000Z
DTEND:20220504T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/107
DESCRIPTION:Title: Bosonization of Fermi Surfaces and Coadjoint Orbits\nby D
am Thanh Son (University of Chicago) as part of ICTS String Seminars\n\n\n
Abstract\nFermi liquid theory is a cornerstone of condensed matter physics
. However\, Landau's formulation of Fermi liquid theory does not fit into
the paradigm of effective field theory. We describe a new method that lead
s to a field-theoretical reformulation of Landau Fermi liquid theory. In t
his approach\, a system with a Fermi surface is described as a coadjoint o
rbit of the group of canonical transformations. The method naturally leads
to a nonlinear bosonization of the Fermi surface. The Berry phase that th
e Fermi surface acquires when changing shape is shown to be given by the K
irillov-Kostant-Souriau symplectic form on the coadjoint orbit. We show th
at the resulting local effective field theory captures both linear and non
linear effects in Landau’s Fermi liquid theory. Possible extensions and
applications of the theory are described. (Reference: Luca Delacrétaz\, U
mang Mehta\, Yi-Hsien Du\, DTS arXiv:2203.05004.)\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/107/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shailesh Lal (U. Porto)
DTSTART:20220601T093000Z
DTEND:20220601T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/108
DESCRIPTION:Title: The World in a Grain of Sand\nby Shailesh Lal (U. Porto)
as part of ICTS String Seminars\n\n\nAbstract\nThe proliferation of vacuum
solutions to string theory highly deter the search for the Standard Model
within the string landscape.\nWe propose a novel approach to this problem
by using machine learning to find a measure of similarity of vacua. Using
complete intersection Calabi Yau manifolds as\na concrete example\, our a
pproach represents these manifolds as points in Euclidean three-space with
similar points clustered together.\nOur analysis provides an explicit met
hod for machine-learning the landscape even with minuscule data.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/108/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Semanti Dutta (IMSc Chennai)
DTSTART:20220608T093000Z
DTEND:20220608T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/109
DESCRIPTION:by Semanti Dutta (IMSc Chennai) as part of ICTS String Seminar
s\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/109/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sayantani Bhattacharya (NISER Bhubaneswar)
DTSTART:20220615T093000Z
DTEND:20220615T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/110
DESCRIPTION:by Sayantani Bhattacharya (NISER Bhubaneswar) as part of ICTS
String Seminars\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/110/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cumrun Vafa (Harvard University)
DTSTART:20220622T093000Z
DTEND:20220622T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/111
DESCRIPTION:by Cumrun Vafa (Harvard University) as part of ICTS String Sem
inars\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/111/
END:VEVENT
BEGIN:VEVENT
SUMMARY:T. R. Ramadas (CMI)
DTSTART:20220728T093000Z
DTEND:20220728T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/112
DESCRIPTION:Title: Symplectic Geometry of $SU(2)$ character varieties and lattic
e gauge theory\nby T. R. Ramadas (CMI) as part of ICTS String Seminars
\n\n\nAbstract\nI present evidence that $SU(2)$ lattice theory integrals o
n a\nfinite lattice can be approximated (in the thermodynamic limit) by\ni
ntegrals over the $SU(2)$ character variety of an associated surface.\nBy
results of Goldman and Jeffrey-Weitsman the formalism of\nDuistermaat-Heck
man applies to the latter.\n(http://arxiv.org/abs/2206.07455)\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/112/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sameer Murthy (King's College\, London)
DTSTART:20220802T100000Z
DTEND:20220802T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/113
DESCRIPTION:Title: Supersymmetric black holes\, the superconformal index\, and p
hases of AdS/CFT\nby Sameer Murthy (King's College\, London) as part o
f ICTS String Seminars\n\n\nAbstract\nLecture 1 of the Infosys-ICTS String
theory lecture series\n\nThe ability to explain the entropy of supersymme
tric black holes from a microscopic\, statistical viewpoint is an importan
t test of any theory of quantum gravity. I will review recent progress on
this problem in the context of the AdS/CFT correspondence. Focussing on Ad
S5/CFT4\, I will show how the entropy of supersymmetric black holes in Ant
i de Sitter space is counted in the microcanonical ensemble by the superco
nformal index of four-dimensional superconformal field theory at large N.
\nIn the grand-canonical ensemble\, the supersymmetric black hole solution
is identified as a saddle-point of the matrix integral representing the s
uperconformal index. I will discuss how this is generalized to an infinite
family of solutions/saddle-points with competing free energies\, which le
ads to an intricate phase structure of the theory. Time permitting\, I wil
l discuss a third interpretation of the superconformal index as an expansi
on in terms of determinants/giant gravitons.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/113/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sameer Murthy (King's College\, London)
DTSTART:20220803T100000Z
DTEND:20220803T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/114
DESCRIPTION:Title: Supersymmetric black holes\, the superconformal index\, and p
hases of AdS/CFT\nby Sameer Murthy (King's College\, London) as part o
f ICTS String Seminars\n\n\nAbstract\nLecture 2 of the Infosys-ICTS String
theory lecture series\n\nThe ability to explain the entropy of supersymme
tric black holes from a microscopic\, statistical viewpoint is an importan
t test of any theory of quantum gravity. I will review recent progress on
this problem in the context of the AdS/CFT correspondence. Focussing on Ad
S5/CFT4\, I will show how the entropy of supersymmetric black holes in Ant
i de Sitter space is counted in the microcanonical ensemble by the superco
nformal index of four-dimensional superconformal field theory at large N.
\nIn the grand-canonical ensemble\, the supersymmetric black hole solution
is identified as a saddle-point of the matrix integral representing the s
uperconformal index. I will discuss how this is generalized to an infinite
family of solutions/saddle-points with competing free energies\, which le
ads to an intricate phase structure of the theory. Time permitting\, I wil
l discuss a third interpretation of the superconformal index as an expansi
on in terms of determinants/giant gravitons.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/114/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sameer Murthy (King's College\, London)
DTSTART:20220805T100000Z
DTEND:20220805T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/115
DESCRIPTION:Title: Supersymmetric black holes\, the superconformal index\, and p
hases of AdS/CFT\nby Sameer Murthy (King's College\, London) as part o
f ICTS String Seminars\n\n\nAbstract\nLecture 3 of the Infosys-ICTS String
theory lecture series\n\nThe ability to explain the entropy of supersymme
tric black holes from a microscopic\, statistical viewpoint is an importan
t test of any theory of quantum gravity. I will review recent progress on
this problem in the context of the AdS/CFT correspondence. Focussing on Ad
S5/CFT4\, I will show how the entropy of supersymmetric black holes in Ant
i de Sitter space is counted in the microcanonical ensemble by the superco
nformal index of four-dimensional superconformal field theory at large N.
\nIn the grand-canonical ensemble\, the supersymmetric black hole solution
is identified as a saddle-point of the matrix integral representing the s
uperconformal index. I will discuss how this is generalized to an infinite
family of solutions/saddle-points with competing free energies\, which le
ads to an intricate phase structure of the theory. Time permitting\, I wil
l discuss a third interpretation of the superconformal index as an expansi
on in terms of determinants/giant gravitons.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/115/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Harlow (MIT)
DTSTART:20220817T123000Z
DTEND:20220817T133000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/117
DESCRIPTION:Title: The black hole interior from non-isometric codes and complexi
ty\nby Daniel Harlow (MIT) as part of ICTS String Seminars\n\n\nAbstra
ct\nI'll give an overview of recent work with Akers\, Engelhardt\, Peningt
on\, and Vardhan\, in which we propose a general framework for understandi
ng the emergence of the black hole interior and the resolution of the info
rmation problem. Many previous ideas\, such as null states\, non-linearit
y\, post-selection\, the QES calculation of the Page curve\, and computati
onal complexity\, arise naturally in this framework.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/117/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Madhu Mishra (IISER Trivandrum)
DTSTART:20220824T093000Z
DTEND:20220824T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/118
DESCRIPTION:Title: Higher derivative action using dilaton Weyl multiplet in four
-dimensional N=2 supergravity\nby Madhu Mishra (IISER Trivandrum) as p
art of ICTS String Seminars\n\n\nAbstract\nIn this talk\, I will focus on
the computational intricacies of building an off-shell higher derivative a
ction in supergravity theory using superconformal tensor calculus. I will
mainly be talking about the construction of the action using dilaton Weyl
multiplet and exploiting the map between dilaton Weyl multiplet and Yang-M
ills multiplet in Poincar\\'e supergravity.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/118/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Moumita Patra (NISER Bhubaneswar)
DTSTART:20220816T103000Z
DTEND:20220816T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/120
DESCRIPTION:Title: Aspects of N=3 Chern-Simons Quiver gauge theories with ADE cl
assification\nby Moumita Patra (NISER Bhubaneswar) as part of ICTS Str
ing Seminars\n\n\nAbstract\nSupersymmetry plays an important role in descr
ibing the dynamics of quantum field theories and string theory. The reason
is that supersymmetry facilitates in computing the quantum corrections.
For example\, in a supersymmetric theory\, some quantities are protected b
y supersymmetry and can be analyzed exactly. In this talk\, we summarize
research on computing some protected quantities\, such as charge of monopo
le operator and superconformal index in three dimensional N=3 superconform
al Chern-Simons matter theories under ADE classification. These quantities
are important as they are aimed at providing checks of AdS_4/CFT_3 corres
pondence.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/120/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Md Abhishek (HRI)
DTSTART:20220830T093000Z
DTEND:20220830T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/121
DESCRIPTION:by Md Abhishek (HRI) as part of ICTS String Seminars\n\nAbstra
ct: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/121/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Julius Julius (King's College London)
DTSTART:20220823T093000Z
DTEND:20220823T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/123
DESCRIPTION:Title: Bootstrability for 1d defect CFT\nby Julius Julius (King'
s College London) as part of ICTS String Seminars\n\n\nAbstract\nIn this t
alk I will describe the “bootstrability” program\, which combines inte
grability techniques in 4d N = 4 SYM and the conformal bootstrap to study
beyond-the-spectrum observables in a CFT.\n\nI will start with a quick rev
iew of the quantum spectral curve (QSC)\, a powerful integrability based m
ethod to compute the non-perturbative planar spectrum of N = 4 SYM. I will
show how it is modified to capture the spectrum of operator insertions on
a 1/2-BPS Maldacena-Wilson line in the theory\, thus solving the spectral
problem of the associated defect CFT.\n\nThen\, I will show how the boost
rability approach allows us to access previously unreachable quantities su
ch as correlation functions at finite coupling — we used this method to
compute with good precision a non-supersymmetric structure constant for a
wide range of the ‘t Hooft coupling in the defect CFT. \n\nFinally\, I w
ill present recent results\, where we included further spectral input\, in
order to derive novel integral constraints for our bootstrap procedure\,
which allows us to improve the precision of our results by several orders
of magnitude.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/123/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vasilis Niarchos (University of Crete)
DTSTART:20220914T093000Z
DTEND:20220914T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/124
DESCRIPTION:Title: 6d (2\,0) bootstrap with soft-Actor-Critic\nby Vasilis Ni
archos (University of Crete) as part of ICTS String Seminars\n\n\nAbstract
\nI will discuss recent efforts to introduce Machine Learning methods in t
he conformal bootstrap programme. The specific approach that I will highli
ght is based on the use of a Reinforcement Learning algorithm\, the soft-A
ctor-Critic algorithm\, which is popular in robotics. As an application\,
I will present results on the conformal bootstrap of the 6d (2\,0) superco
nformal field theories\, where we have recently obtained some new encourag
ing results.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/124/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sayali Bhatkar (TIFR)
DTSTART:20220928T093000Z
DTEND:20220928T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/125
DESCRIPTION:by Sayali Bhatkar (TIFR) as part of ICTS String Seminars\n\nAb
stract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/125/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Berenstein (UC\, Santa Barbara)
DTSTART:20220826T060000Z
DTEND:20220826T070000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/126
DESCRIPTION:Title: BPS coherent states and localization\nby David Berenstein
(UC\, Santa Barbara) as part of ICTS String Seminars\n\n\nAbstract\nI wil
l describe recent results on writing coherent stars for bps n=4 sym in ter
ms of unitary matrix integrals and some variations of these ideas. For the
case of half bps states\, these integrals can be done via localization. T
his suggests ways to do calculations of open strings attached to giant gra
vitons more systematically\, by focusing on the perturbation theory of the
dominant saddle.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/126/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Irene Valenzuela (CERN)
DTSTART:20221019T093000Z
DTEND:20221019T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/128
DESCRIPTION:Title: At the Boundary of the Swampland\nby Irene Valenzuela (CE
RN) as part of ICTS String Seminars\n\n\nAbstract\nQuantum gravitational e
ffects can become important at scales much below the Planck scale. This oc
curs\, for instance\, when approaching infinite distance boundaries of the
field space of string compactifications. These boundaries share some univ
ersal properties that are promoted to Swampland constraints (i.e. constrai
nts that any EFT must satisfy to be consistent with quantum gravity)\, lik
e the presence of an infinite tower of states becoming light asymptoticall
y or a runway behaviour for the scalar potential. I will discuss recent de
velopments on classifying these boundaries and characterizing these proper
ties\, both in the context of stringy Calabi-Yau compactifications as well
as from the perspective of the CFT conformal manifold when there is an Ad
S vacuum. This can allow us to answer phenomenologically relevant question
s like whether string theory allows for asymptotic accelerated cosmologies
at late times\, or the possible presence of these light towers of states
in our universe.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/128/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atish Dabholkar (ICTP\, Trieste)
DTSTART:20221014T123000Z
DTEND:20221014T140000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/129
DESCRIPTION:Title: Quantum Entanglement in String Theory\nby Atish Dabholkar
(ICTP\, Trieste) as part of ICTS String Seminars\n\n\nAbstract\nI describ
e partial progress in defining classical and quantum entanglement entropy
in string theory using the orbifold method and discuss the physical motiva
tions from holography and black hole physics.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/129/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shiraz Minwalla (TIFR)
DTSTART:20221007T053000Z
DTEND:20221007T063000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/130
DESCRIPTION:Title: Crossing Symmetry in Matter Chern Simons Theories at finite N
and k\nby Shiraz Minwalla (TIFR) as part of ICTS String Seminars\n\n\
nAbstract\nI present a conjecture for the crossing symmetry rules for Cher
n Simons gauge theories interacting with massive matter in $2 + 1$\n dimen
sions. These crossing rules are are given in terms of the expectation valu
es of particular tangles of Wilson lines\, and reduce\nto the standard rul
es at large Chern Simons level. I will present completely explicit results
\nfor the special case of two fundamental and two antifundamental insertio
ns in $SU (N )_k$\nand $U (N )_k$ theories. These formulae are consistent
with the conjectured Level-Rank\, Bose\nFermi duality between there theori
es and take the form of a q deformation of their\nlarge k counterparts. I
n the 't Hooft large $N$ limit our results reduce to standard rules with\n
one twist: the S matrix in the singlet channel is reduced by the factor $\
\sin \\pi\\lambda/\\pi\\lambda$(where $\\lambda$ is\nthe 't Hooft coupling
)\, explaining `anomalous' crossing properties observed in earlier direct\
nlarge $N$ computations.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/130/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jack Holden (Southampton U.)
DTSTART:20221109T093000Z
DTEND:20221109T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/131
DESCRIPTION:Title: Partial deconfinement\nby Jack Holden (Southampton U.) as
part of ICTS String Seminars\n\n\nAbstract\nIn large-$N$ gauge theories\,
evidence has emerged recently that between confined and deconfined phases
a partially-deconfined phase can appear\, in which only a subset of colou
rs deconfine. The existence of such a phase has implications for the map b
etween degrees of freedom under gauge/gravity duality and black hole phase
diagrams\, where a counterpart to the partially-deconfined saddle should
be present. We investigate properties of partial deconfinement on the fiel
d theory side\, first considering the partially-deconfined saddle of large
-$N$ pure Yang-Mills theory. Here\, the colour degrees of freedom split in
to confined and deconfined sectors. We argue with the use of numerical sim
ulations that a linear confinement potential is generated in the confined
sector\, implying the formation of flux tubes\, whereas the potential is s
creened in the deconfined sector and behaves instead according to the peri
meter law. Furthermore\, we find that the onset of partial deconfinement c
oincides with the breaking of chiral symmetry\, providing an order paramet
er for the partially-deconfined phase. We conjecture that global symmetrie
s can be used to signify partial deconfinement\, leading also to an associ
ated order parameter. As another\, cleaner example of this\, we show that
CP symmetry breaking coincides precisely with the emergence of the partial
ly-deconfined phase in supersymmetry-broken $N=1$ super-Yang-Mills with a
theta-angle $\\theta=\\pi$\, for both large finite $N$ and the formal larg
e-$N$ limit. Finally\, we discuss consequences of these findings for holog
raphy and the QCD crossover.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/131/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ayan Mukhopadhyay (IIT Madras)
DTSTART:20221116T093000Z
DTEND:20221116T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/132
DESCRIPTION:Title: Black hole microstate models\, quantum weak measurement and b
lack hole complementarity\nby Ayan Mukhopadhyay (IIT Madras) as part o
f ICTS String Seminars\n\n\nAbstract\nWe will introduce a class of black h
ole microstate models which mimic classical black holes in terms of energy
absorption and relaxation properties\, while demonstrating how black hole
complementarity emerges from microscopic dynamics. We will focus on quant
um information mirroring in particular and show how information can be cop
ied twice in non-linear quantum channels realized by in the local (but not
global) semi-classical approximation. These non-linear quantum channels m
imic dynamically realized quantum weak measurement with new features that
need to be understood in terms of von Neumann algebras. Our models can be
potentially simulated in the laboratory.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/132/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aninda Sinha (Indian Institute of Science)
DTSTART:20221026T093000Z
DTEND:20221026T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/133
DESCRIPTION:by Aninda Sinha (Indian Institute of Science) as part of ICTS
String Seminars\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/133/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sachin Jain (IISER Pune)
DTSTART:20221124T093000Z
DTEND:20221124T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/134
DESCRIPTION:Title: Anyons and bosonization in 3d: Mapping slightly broken Higher
spin (SBHS) theory correlator to Free theory correlator.\nby Sachin J
ain (IISER Pune) as part of ICTS String Seminars\n\nLecture held in Madhav
a Hall- ICTS.\n\nAbstract\nWe develop a systematic method to compute the a
ny n-point function of any spin current operator for SBHS theories which
are also known as Chern-Simons matter theories. When expressed in spinor-h
elicity variables we obtain an anyonic phase which nicely interpolates bet
ween the free fermionic and critical bosonic results which makes 3D bosoni
zation manifest.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/134/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mukund Rangamani (UC Davis)
DTSTART:20221110T103000Z
DTEND:20221110T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/135
DESCRIPTION:Title: Lessons from holography for open quantum systems\nby Muku
nd Rangamani (UC Davis) as part of ICTS String Seminars\n\n\nAbstract\nWe
describe general lessons one can glean about the effective dynamics of ope
n quantum systems using holography. Specifically\, we will argue that usin
g holographic CFTs to provide thermal environments is a useful way to extr
act the broad physical principles. This turns out to be especially useful
when the probe system long-lived gapless modes of the environment. To ill
ustrate the ideas\, we will also motivate a simple class of toy models tha
t captures all the essential physics. As a corollary we also explain analy
tic properties of real-time thermal correlation functions.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/135/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luis Alday (U. Oxford)
DTSTART:20221129T093000Z
DTEND:20221129T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/136
DESCRIPTION:Title: AdS Virasoro-Shapiro from single-valued periods\nby Luis
Alday (U. Oxford) as part of ICTS String Seminars\n\n\nAbstract\nWe determ
ine the full $1/\\lambda$ correction to the flat-space Wilson coefficients
which enter the AdS Virasoro-Shapiro amplitude in N = 4 SYM theory at str
ong coupling. The assumption that the Wilson coefficients are in the ring
of single-valued multiple zeta values\, as expected for closed string ampl
itudes\, is surprisingly powerful and leads to a unique solution to the di
spersive sum rules relating Wilson coefficients and OPE data obtained in a
n earlier work. The corresponding OPE data fully agrees with and extends t
he results from integrability. The $\\sqrt{\\lambda}$ can be summed into a
n expression whose structure of poles Wilson coefficients to order $1/ \\s
qrt{\\lambda}$ and residues generalises that of the Virasoro-Shapiro ampli
tude in flat space.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/136/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arnab Rudra (IISER Bhopal)
DTSTART:20221207T093000Z
DTEND:20221207T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/137
DESCRIPTION:by Arnab Rudra (IISER Bhopal) as part of ICTS String Seminars\
n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/137/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arnab Rudra (IISER Bhopal)
DTSTART:20221216T093000Z
DTEND:20221216T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/138
DESCRIPTION:Title: On-shell Supersymmetry and higher-spin amplitudes\nby Arn
ab Rudra (IISER Bhopal) as part of ICTS String Seminars\n\n\nAbstract\nWe
investigate the constraint from supersymmetry on the interaction of higher
spin particles. We use on-shell Supersymmetry to constrain the three-poin
t function of two massless particles and one massive particle in 3+1 dimen
sions. We use this framework to write down the tree-level four-point funct
ion of massless particles for theories with 4\, 8 and 16 supercharges. In
particular\, we derive the expressions for four-photon/gluon amplitudes wi
th a massive higher spin exchange in theories with N=4 Supersymmetry in 3+
1 dimensions. If time permits\, we will mention the extension of this stor
y to higher dimensions. \n\nReference: The talk is primarily based on 2209
.06446 and the references mentioned in that preprint.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/138/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sunil Mukhi (IISER Pune)
DTSTART:20230118T093000Z
DTEND:20230118T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/139
DESCRIPTION:Title: Rational Conformal Field Theories With A Single Critical Expo
nent\, and Their Classification\nby Sunil Mukhi (IISER Pune) as part o
f ICTS String Seminars\n\n\nAbstract\nI will present a classification of a
ll unitary\, rational\nconformal field theories with two primaries\, centr
al charge c < 25\,\nand arbitrary Wronskian index. (Work in collaboration
with Brandon\nRayhaun\, arXiv: 2208.05486). These are shown to be either
certain\nlevel-1 WZW models or cosets of meromorphic theories by such mode
ls.\nBy leveraging the existing classification of meromorphic CFTs of\nce
ntral charge c ≤ 24\, all the relevant cosets are enumerated and\ntheir
characters computed. This leads to 123 theories\, most of which\nare new.
It will be emphasised that this is a classification of RCFTs\nand not just
consistent characters. Related recent work with Arpit Das\nand Chethan Go
wdigere will also be surveyed.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/139/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mrityunjay Verma (University of Southampton)
DTSTART:20230117T093000Z
DTEND:20230117T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/140
DESCRIPTION:Title: Scale Invariant EFTs in Holography\nby Mrityunjay Verma (
University of Southampton) as part of ICTS String Seminars\n\n\nAbstract\n
I shall discuss an ongoing work which aims to investigate the issue of sca
le vs conformal invariance in the context of AdS/CFT. We consider the most
general 4 derivative EFTs involving gravity and a scalar field in AdS. We
show that this system admits a solution which breaks the full conformal i
nvariance to just Poincare and scaling. However\, a puzzle arises since it
does not have the correct 2 point function and anomaly consistent with ju
st having scale but no conformal invariance in the theory. We next compare
the theory to Horndeski gravity with scalar which also admits a solution
having scale but no conformal invariance. However\, this theory has proper
2 point function and anomalies expected in such a theory. However\, this
leads to a puzzle since we can map our theory to Horndeski theory by a fie
ld redefinition.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/140/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Harvey Reall (University of Cambridge)
DTSTART:20230125T093000Z
DTEND:20230125T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/141
DESCRIPTION:Title: The second law of black hole mechanics in effective field the
ory\nby Harvey Reall (University of Cambridge) as part of ICTS String
Seminars\n\n\nAbstract\nI shall discuss the second law of black hole mecha
nics in gravitational theories with higher derivative terms in the action.
Wall has described a method for defining an entropy that satisfies the se
cond law to linear order in perturbations around a stationary black hole.
I shall explain how this can be extended to define an entropy that satisfi
es the second law to quadratic order in perturbations\, provided that one
treats the higher derivative terms in the sense of effective field theory.
This talk is based on work with Stefan Hollands\, Aron Kovacs and Iain Da
vies.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/141/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Surbhi Ketrapal (University of Hyderabad)
DTSTART:20230124T101000Z
DTEND:20230124T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/142
DESCRIPTION:by Surbhi Ketrapal (University of Hyderabad) as part of ICTS S
tring Seminars\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/142/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Swapnamay Mondal (Trinity College\, Dublin)
DTSTART:20230131T101000Z
DTEND:20230131T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/143
DESCRIPTION:Title: Supersymmetric black holes and $T\\bar{T}$ deformation\nb
y Swapnamay Mondal (Trinity College\, Dublin) as part of ICTS String Semin
ars\n\n\nAbstract\nThe entropy of supersymmetric black holes in string the
ory\ncompactifications can be related to that of a D- or M-brane system\,
which\nin many cases can be further reduced to a two-dimensional conformal
field\ntheory (2d CFT). For black holes in M-theory\, this relation invol
ves a\ndecoupling limit where the black hole mass diverges. We suggest tha
t\nmoving away from this limit corresponds to a specific irrelevant\npertu
rbation of the 2d CFT\, namely the supersymmetric completion of the T\n\\b
ar{T} deformation. We demonstrate that the black hole mass matches\nprecis
ely with the T \\bar{T} deformed energy levels\, upon identifying the\nT \
\bar{T} deformation parameter with the inverse of the leading term of\nthe
black hole mass. We discuss implications of this novel realization of\nth
e T \\bar{T} deformation\, including a Hagedorn temperature for wrapped\nM
5-branes.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/143/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andreas Karch (University of Texas\, Austin)
DTSTART:20230201T130000Z
DTEND:20230201T143000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/144
DESCRIPTION:Title: A top-down dictionary for double holography\nby Andreas K
arch (University of Texas\, Austin) as part of ICTS String Seminars\n\n\nA
bstract\nHolographic interpretations of Randall-Sundrum (RS) branes \nprov
ide a laboratory to explore the way quantum information evolves in \nfield
theories coupled to gravity. Despite this importance\, the \nholographic
interpretation of RS branes in terms of a theory of gravity \ncoupled to a
CFT is rather ad-hoc. In this talk\, we use top-down \nconstructions of R
S branes in order to work out a precise dictionary for \nthis "intermediat
e" holographic prescription\, resolving serious \ncausality problems of th
e naive picture often used in the literature \nwhile preserving many of th
e successes of the RS construction.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/144/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aradhita Chattopadhyaya (Dublin Institute for Advanced Studies)
DTSTART:20230208T093000Z
DTEND:20230208T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/145
DESCRIPTION:Title: Numerical experiments on coefficients of instanton partition
functions\nby Aradhita Chattopadhyaya (Dublin Institute for Advanced S
tudies) as part of ICTS String Seminars\n\n\nAbstract\nWe analyze the coef
ficients of partition functions of \nVafa-Witten theory for the complex pr
ojective plane \nℂℙ2. We experimentally study the growth of the coeffi
cients for \ngauge group SU(2) and SU(3)\, which are examples of mock modu
lar \nforms of depth 1 and 2 respectively. We also introduce the notion of
``mock cusp \nform''\, and study an example of weight 3 related to the SU
(3) partition function. \nNumerical experiments on the first 200 coefficie
nts suggest that the \ncoefficients of a mock modular form of weight k gro
w as the \ncoefficients of a modular form of weight k\, that is to say as
\nnk−1. On the other hand the coefficients of the mock cusp form \nappea
r to grow as n3/2\, which exceeds the growth of classical \ncusp forms of
weight 3. We \nprovide bounds using saddle point analysis\, which however
largely exceed the \nexperimental observation.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/145/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Meseret Asrat (ICTS\, Bangalore)
DTSTART:20230215T093000Z
DTEND:20230215T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/146
DESCRIPTION:Title: (1+1)D QCD with heavy adjoint quarks\nby Meseret Asrat (I
CTS\, Bangalore) as part of ICTS String Seminars\n\n\nAbstract\nIn this ta
lk\, I will discuss confinement in adjoint QCD in two spacetime dimensions
. In particular\, I will derive from first principles the non-relativistic
Schrodinger equation that describes the low-lying bound states of the two
dimensional adjoint QCD in the limit of heavy quark masses and large numb
er of colors. I will discuss the spectrum of bound states of two and three
adjoint quarks. I will also present the associated classical many body sy
stem. I will show that the system is sensitive to initial conditions. Chao
tic dynamical systems are in particular known to exhibit such behavior. In
general\, it might be of interest to gain insights into chaos theory. The
talk is based on my recent paper: arXiv:2212.02162[hep-th]\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/146/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoffrey R. Penington (UC\, Berkeley)
DTSTART:20230222T060000Z
DTEND:20230222T073000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/147
DESCRIPTION:Title: Algebras and states in JT gravity\nby Geoffrey R. Peningt
on (UC\, Berkeley) as part of ICTS String Seminars\n\n\nAbstract\nWe analy
ze the algebra of boundary observables in canonically quantised JT gravity
with or without matter. In the absence of matter\, this algebra is commut
ative\, generated by the ADM Hamiltonian. After coupling to a bulk quantum
field theory\, it becomes a highly noncommutative algebra of Type II infi
nity with a trivial center. As a result density matrices and entropies on
the boundary algebra are uniquely defined upto\, respectively\, a rescalin
g or shift. We show that this algebraic definition of entropy agrees with
the usual replica trick definition computed using Euclidean path integrals
. Unlike in the previous arguments that focussed on O(1) fluctuations to a
black hole of specified mass\, this type II infinity algebra describes st
ates at all temperatures or energies.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/147/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kajal Singh (HRI\, Allahabad)
DTSTART:20230314T103000Z
DTEND:20230314T120000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/148
DESCRIPTION:Title: Joint Statistics of Cosmological Constant and SUSY Breaking S
cale in Flux Vacua with Nilpotent Goldstino.\nby Kajal Singh (HRI\, A
llahabad) as part of ICTS String Seminars\n\n\nAbstract\nWe obtain the joi
nt distribution of the gravitino mass and the \ncosmological constant in K
KLT and LVS models with anti-D3 brane \nuplifting described via the nilpot
ent goldstino formalism. Moduli \nstabilisation (of both complex structure
and Kähler moduli) is \nincorporated so that we sample only over points
corresponding to vacua. \nOur key inputs are the distributions of the flux
superpotential\, the \nstring coupling\, and the hierarchies of warped th
roats. In the limit of \nzero cosmological constant\, we find that both in
KKLT and LVS\, the \ndistributions are tilted favourably towards lower sc
ales of \nsupersymmetry breaking.\n(Based on https://arxiv.org/pdf/2211.07
695.pdf.)\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/148/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vaibhav Kalvakota (Turito Institute)
DTSTART:20230301T101500Z
DTEND:20230301T114500Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/149
DESCRIPTION:Title: Aspects of the Generalized Second Law and the Covariant Entro
py bound\nby Vaibhav Kalvakota (Turito Institute) as part of ICTS Stri
ng Seminars\n\n\nAbstract\nIn this talk\, we will look at generalized entr
opy and the generalized second law in the perspective of singularities. We
will review the GSL in a cosmological perspective\, and find motivation t
owards the GSL and entropy based singularity theorems. We will see how the
fine-grained GSL and the covariant entropy bound provide a physical tool
for singularity theorems\, replacing topological conditions such as the pr
esence of a non-compact Cauchy surface with instead the quantum focusing c
onjecture. We will then discuss further aspects of the GSL such as quantum
holographic screens in different cosmologies\, and if time permits we wil
l provide an outlook for the role of generalized entropy in the asymptotic
nature of null hypersurfaces\, which will formulate a quantum Penrose ine
quality for null hypersurfaces on the basis of the generalized entropy.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/149/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Tong (DAMTP\, Cambridge)
DTSTART:20230322T093000Z
DTEND:20230322T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/150
DESCRIPTION:Title: A Chern-Simons Theory for the Indian Ocean\nby David Tong
(DAMTP\, Cambridge) as part of ICTS String Seminars\n\n\nAbstract\nIn som
e ways the ocean acts like a topological insulator. There are chiral edge
modes\, localised at the coast\, that go clockwise in the Northern hemisph
ere and anti-clockwise in the Southern hemisphere. I’ll describe these
features and explain how this can be understood in terms of something more
familiar to high energy physicists. I’ll show that the equations that g
overn the long-time dynamics of the ocean can be recast as a Maxwell-Chern
-Simons theory.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/150/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pratik Rath (UC\, Santa Barbara)
DTSTART:20230313T103000Z
DTEND:20230313T120000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/151
DESCRIPTION:Title: Modular Flow in Holographic Theories of Gravity\nby Prati
k Rath (UC\, Santa Barbara) as part of ICTS String Seminars\n\n\nAbstract\
nIn this talk\, I will prove from first principles that modular flow in Ad
S/CFT can be well approximated by a kink transform on the classical spacet
ime. In order to do so\, I will discuss a formulation of holography as app
roximate quantum error correction using a large code subspace consisting o
f multiple background geometries. The large code subspace allows us to dis
cuss the bulk dual of modular flow which affects the background geometry i
n a non-trivial manner. We discuss situations where modular flow can be we
ll approximated by classical flow by the HRT area operator\, and using the
Peierls bracket technique\, derive the fact that modular flow approximate
ly acts by a kink transform. These results generalize to higher derivative
theories and constitute a new Lorentzian derivation of the geometric entr
opy.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/151/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luca Ilisieu (Stanford University)
DTSTART:20230412T133000Z
DTEND:20230412T153000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/152
DESCRIPTION:Title: On the quantum mechanics of near-extremal black holes\nby
Luca Ilisieu (Stanford University) as part of ICTS String Seminars\n\n\nA
bstract\nIn the past years\, quantum effects in the gravitational path int
egral have given us an accurate picture of how black holes behave close to
extremality. In particular\, while most modes in this path integral can b
e treated quadratically\, a particular set of modes\, the modes of JT grav
ity\, are strongly coupled and lead to large quantum corrections for the l
ow-temperature partition function. I shall review these developments\, des
cribing our new understanding of the behavior of both supersymmetric and n
on-supersymmetric black holes.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/152/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Onkar Parikkar (TIFR\, Mumbai)
DTSTART:20230329T103000Z
DTEND:20230329T120000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/153
DESCRIPTION:Title: Canonical Purification\, Bulk reconstruction and the Quantum
extremal shock\nby Onkar Parikkar (TIFR\, Mumbai) as part of ICTS Stri
ng Seminars\n\n\nAbstract\nWe will discuss the canonical purification (wit
h respect to one of the parties) of pure\, bi-partite states obtained by t
urning on sources in the Euclidean path integral. In holographic conformal
field theories\, the Lorentzian bulk dual of the canonical purification c
onsists of the corresponding entanglement wedge glued to its CPT image at
the quantum extremal surface. However\, the mismatch in the classical expa
nsions at the QES due to quantum corrections needs to be supported by a sh
ock in the bulk matter stress tensor in order for the bulk to satisfy Eins
tein's equations. Working perturbatively to first order in double-trace so
urces around the thermofield double state\, we will demonstrate that the s
tate of the bulk matter in the dual to the canonically purified boundary C
FT state precisely has this quantum extremal shock in the bulk stress tens
or. Along the way\, we will discuss applications of these results to entan
glement wedge reconstruction beyond HKLL.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/153/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atakan Hilmi Farat (MIT)
DTSTART:20230405T110000Z
DTEND:20230405T120000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/154
DESCRIPTION:Title: Bootstrapping closed string field theory\nby Atakan Hilmi
Farat (MIT) as part of ICTS String Seminars\n\n\nAbstract\nClosed string
field theory is a second-quantized formalism for string theory. It demands
a choice of string vertices that involve solving certain geometrical stru
ctures on Riemann surfaces and their moduli spaces. In this talk\, I demon
strate that determining hyperbolic string vertices of Costello-Zwiebach is
a conformal bootstrap problem in the context of Liouville theory. The con
sequences are explored. Based on 2302.12843.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/154/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chethan Krishnan (IISc\, Bangalore)
DTSTART:20230419T093000Z
DTEND:20230419T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/155
DESCRIPTION:Title: Fuzzballs and Random Matrices\nby Chethan Krishnan (IISc\
, Bangalore) as part of ICTS String Seminars\n\n\nAbstract\nIt is sometime
s said that the fuzzball proposal cannot incorporate the chaos/random matr
ix aspects of black holes. We will instead observe that the linear ramp an
d level repulsion are essentially inevitable in black hole spacetimes with
out an interior\, if one does not ignore the angular directions of the geo
mery.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/155/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vijay Balasubramaniam (University of Pennsylvania)
DTSTART:20230503T093000Z
DTEND:20230503T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/156
DESCRIPTION:Title: Microscopic origin of the entropy of black holes in general r
elativity\nby Vijay Balasubramaniam (University of Pennsylvania) as pa
rt of ICTS String Seminars\n\n\nAbstract\nI will construct an infinite fam
ily of microstates with geometric interiors for eternal black holes in gen
eral relativity with negative or vanishing cosmological constant in any di
mension. Wormholes in the Euclidean path integral for gravity cause these
states to have small\, but non-zero\, quantum mechanical overlaps that hav
e a universal form. The overlaps have a dramatic consequence: the microsta
tes span a Hilbert space of log dimension equal to the Bekenstein-Hawking
entropy. The semiclassical microstates we construct contain Einstein-Rosen
bridges of arbitrary size behind their horizons. Our results imply that a
ll these bridges can be interpreted as quantum superpositions of wormholes
of size at most exponential in the entropy.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/156/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ahmed Almhieri (NYU Abu Dhabi)
DTSTART:20230426T093000Z
DTEND:20230426T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/157
DESCRIPTION:Title: The final state proposal: Making sense of measurement probabi
lities & prescription for computing entropy.\nby Ahmed Almhieri (NYU A
bu Dhabi) as part of ICTS String Seminars\n\n\nAbstract\nI will discuss th
e status of the Horowitz-Maldacena final state proposal as a mechanism for
allowing information to escape a black hole while also maintaining a smoo
th horizon. I will explain the measurement paradox of Bousso-Stanford and
a possible resolution inspired by replica wormholes and its limitations. F
inally\, I will discuss work in progress proposing a method to compute ent
anglement entropy in the presence of a final state.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/157/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eva Silverstein (Stanford U.)
DTSTART:20230524T140000Z
DTEND:20230524T153000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/158
DESCRIPTION:Title: The matter with TT-bar + Lambda_2\nby Eva Silverstein (St
anford U.) as part of ICTS String Seminars\n\n\nAbstract\nThe solvable TT-
bar(+Λ2) deformation of holographic CFTs recently provided an explicit mi
crostate count for the dS3 cosmic horizon\, reproducing the refined Gibbon
s-Hawking entropy computed by Anninos et al along with the correct emergen
t radial bulk geometry.\nThis meshes with other work deriving the standard
first law sign in bounded regions of dS and the flat entanglement spectru
m in the global dS ground state. To build from this\, we develop the corr
espondence toward incorporating the (subleading) effects of local bulk mat
ter fields\, adding contributions to the differential equation describing
the deformation to capture local bulk gauge and scalar fields. This presc
ription retains the finiteness of the real ls spectrum (hence a type I Von
Neumann algebra for finite Newton’s constant)\, without the need for th
e strong factorization properties of TT-bar(+Λ2) alone. Thanks to the ti
melike boundary\, the duality is relatively close to AdS/CFT\, including n
on-dynamical boundary gravity and AdS-like Gao-Wald (causal) behavior upon
excitation in a bounded patch. Finally\, we resolve a a puzzle concernin
g the embedding of the deformation in string/M theory\, finding a new role
for (internal) averaging in quantum gravity.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/158/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Suresh Govindarajan (IIT Madras)
DTSTART:20230517T093000Z
DTEND:20230517T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/159
DESCRIPTION:Title: Lie algebras from Counting of Dyonic Degeneracies\nby Sur
esh Govindarajan (IIT Madras) as part of ICTS String Seminars\n\n\nAbstrac
t\nThe generating functions (and refinements thereof) of the \ndegeneracie
s of quarter BPS states in four-dimensional N=4 \nsupersymmetric theories
that arise from type II compactifications on \nK3XT2 and its asymmetric CH
L orbifolds are genus-two Siegel modular \nforms. In some of the cases\, t
he walls of marginal stability across \nwhich two-centred BPS states decay
into single centered ones lead to \nrank-three Lorentzian root lattices w
ith Weyl vector. In all but three \nexamples\, the square-roots of generat
ing functions\, are the \nWeyl-Kac-Borcherds denominator formula for some
Borcherds-Kac-Moody \n(BKM) Lie superalgebra. Rank-three Lorentzian lattic
es with Weyl vectors \nhave been classified long ago by Nikulin. The three
examples\, that do not \nhave an Lie algebraic interpretation\, have Weyl
vectors of hyperbolic \ntype. Gritsenko and Nikulin have a no-go theorem
that states that such \nLorentzian lattices are not related to any BKM Lie
superalgebra.\n\nThe dyon generating functions lead to potential denomina
tor formulae for \na new kind of Lie superalgebra. We study these denomina
tor formulae in \nterms of an affine sl(2) subalgebra and a Borcherds exte
nsion of the \naffine sl(2) subalgebra. We discuss our studies on the deco
mposition of \nthe potential denominator formula in terms of the character
s of both \nsub-algebras. An important result is the appearance of fermion
ic roots \nwith unusual behaviour. We are able to characterise the multipl
icity of \nvarious imaginary simple roots in terms of vector valued modula
r forms \nfor which we can give closed formulae in some cases.\n\nBased on
: arXiv:2106.01605 and arXiv:2207.10502\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/159/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sean Hartnoll (University of Cambridge)
DTSTART:20230510T093000Z
DTEND:20230510T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/160
DESCRIPTION:Title: Wheeler-DeWitt states of black hole and cosmological interior
s.\nby Sean Hartnoll (University of Cambridge) as part of ICTS String
Seminars\n\n\nAbstract\nIn AdS/CFT\, the renormalization group flow of cou
pling constants is described by the radial evolution of bulk fields\, usin
g the bulk equations of motion. Horizons in the bulk correspond to the far
IR of the renormalisation group\, but the bulk evolution does not stop th
ere. The bulk fields continue to evolve in the “interior” beyond the h
orizon\, with the evolution now unfolding in time rather than space. In th
e interior the same bulk equations of motion now define a Wheeler-DeWitt w
ave function rather than a boundary partition function. I will explain how
Hamilton-Jacobi theory gives a unified description of the exterior partit
ion function of coupling constants and the interior wave function. Once th
is picture is established in AdS/CFT\, I will describe how it can be appli
ed also in de Sitter spacetimes. There\, the same equations defining Wheel
er-DeWitt states near future infinity are shown to define quantum mechanic
al partition functions in the static patch.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/160/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Abhijit Gadde (TIFR)
DTSTART:20230531T093000Z
DTEND:20230531T113000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/161
DESCRIPTION:Title: Towards classification of probe measures of multipartite enta
nglement\nby Abhijit Gadde (TIFR) as part of ICTS String Seminars\n\nA
bstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/161/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Abhiram Kidambi (IPMU\, Japan)
DTSTART:20230427T083000Z
DTEND:20230427T100000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/162
DESCRIPTION:Title: Connections between number theory and physics (Part 1)\nb
y Abhiram Kidambi (IPMU\, Japan) as part of ICTS String Seminars\n\nAbstra
ct: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/162/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Abhiram Kidambi (IPMU\, Japan)
DTSTART:20230501T101500Z
DTEND:20230501T120000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/163
DESCRIPTION:Title: Connections between number theory and physics(Part 2)\nby
Abhiram Kidambi (IPMU\, Japan) as part of ICTS String Seminars\n\nAbstrac
t: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/163/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shailesh Chandrasekharan (Duke University)
DTSTART:20230511T093000Z
DTEND:20230511T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/164
DESCRIPTION:Title: Learning more about the magic of Wilson’s Renormalization G
roup\nby Shailesh Chandrasekharan (Duke University) as part of ICTS St
ring Seminars\n\n\nAbstract\nIt is well known that continuum quantum field
theories can emerge from lattice field theories when the latter are tuned
to critical points. However\, this understanding has taken a somewhat mag
ical twist in recent years\, where we are able to show that free Gaussian
field theories with marginally relevant couplings seem to emerge at long d
istances from just a few discrete lattice degrees of freedom. After quickl
y reviewing an older result in the O(3) nonlinear sigma model which showed
us this phenomenon\, I will demonstrate that something similar occurs in
the well-known BKT transition. Apparently\, a simple loop-gas model on a s
quare lattice with three degrees of freedom per lattice site can reproduce
the massive phase of the transition automatically fine-tuned to the trans
ition. An interesting question for the future is whether these few isolate
d cases we have seen are just “tips of icebergs” of a more elaborate h
idden approach to other continuum quantum field theories.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/164/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shiraz Minwalla (TIFR)
DTSTART:20230519T060000Z
DTEND:20230519T073000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/165
DESCRIPTION:Title: The endpoint of the Kerr-AdS super-radiant Instability\nb
y Shiraz Minwalla (TIFR) as part of ICTS String Seminars\n\n\nAbstract\nKe
rr-AdS$_{d+1}$ black holes for $d\\geq 3$ suffer from classical superradia
nt instabilities over a range of masses above extremality. We conjecture t
hat these instabilities settle down into Grey Galaxies (GGs) - a new class
of coarse-grained solutions to Einstein's equations which we construct in
$d=3$. Grey Galaxies are made up of a black hole with critical angular ve
locity $\\omega=1$ in the `centre' of $AdS$\, surrounded by a large flat
disk of thermal bulk gas that revolves around the centre of $AdS$ at the s
peed of light. The gas carries a finite fraction of the total energy\, as
its parametrically low energy density and large radius are inversely relat
ed. GGs exist at masses that extend all the way down to the unitarity boun
d. Their thermodynamics is that of a weakly interacting mix of Kerr-AdS bl
ack holes and the bulk gas. Their boundary stress tensor is the sum of a s
mooth `black hole' contribution and a peaked gas contribution that is delt
a function localized around the equator of the boundary sphere in the larg
e $N$ limit. We also construct another class of solutions with the same ch
arges\; `Revolving Black Holes (RBHs)'. RBHs are macroscopically charged
$SO(d\,2)$ descendants of AdS-Kerr solutions\, and consist of $\\omega=1$
black holes revolving around the centre of $AdS$ at a fixed radial locati
on but in a quantum wave function in the angular directions. RBH solutions
are marginally entropically subdominant to GG solutions\, and do not cons
titute the endpoint of the superradiant instability. Nonetheless\, we argu
e that supersymmetric versions of these solutions have interesting implica
tions for the spectrum of supersymmetric states in\, e.g. ${\\cal N}=4$ Y
ang-Mills theory.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/165/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alok Laddha (CMI)
DTSTART:20230518T053000Z
DTEND:20230518T073000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/166
DESCRIPTION:Title: From Avatars of Associahedron to S-matrix of scalar field the
ories\nby Alok Laddha (CMI) as part of ICTS String Seminars\n\nAbstrac
t: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/166/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dileep Jatkar (HRI)
DTSTART:20230601T093000Z
DTEND:20230601T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/167
DESCRIPTION:Title: Utility of the DBI counter-term\nby Dileep Jatkar (HRI) a
s part of ICTS String Seminars\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/167/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Victoria Martin (U. Iceland)
DTSTART:20230621T093000Z
DTEND:20230621T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/168
DESCRIPTION:Title: Lessons from the quotient structure of spacetime: Flat space
cosmology edition\nby Victoria Martin (U. Iceland) as part of ICTS Str
ing Seminars\n\n\nAbstract\nIn this talk we consider spacetimes that are q
uotients (such as the BTZ black hole\, warped AdS black holes\, flat space
cosmologies\, and many more). We ask the question: what can we learn from
the quotient structure of spacetime alone? The answer: from the quotient
group we can construct a Selberg-like zeta function (a close cousin of the
Riemann zeta function) that produces the one-loop partition function for
a probe scalar field and the corresponding quasinormal modes. We focus in
particular on our forthcoming work studying this mechanism in flat space c
osmologies (also known as symmetric boost orbifolds). Generalizations to
higher spin fields beyond the scalar field example are straightforward.\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/168/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rajath Radhakrishnan (ICTP)
DTSTART:20230629T093000Z
DTEND:20230629T103000Z
DTSTAMP:20260404T095121Z
UID:ictsvirtual/169
DESCRIPTION:by Rajath Radhakrishnan (ICTP) as part of ICTS String Seminars
\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/ictsvirtual/169/
END:VEVENT
END:VCALENDAR