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BEGIN:VEVENT
SUMMARY:Phil Saad (Stanford)
DTSTART:20200622T180000Z
DTEND:20200622T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/1
DESCRIPTION:Title: Some comments about wormholes and factorization\nby Phil Saad
(Stanford) as part of Theoretical Physics Seminars (Kentucky)\n\nAbstract:
TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robert Brandenberger (McGill University)
DTSTART:20200824T180000Z
DTEND:20200824T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/2
DESCRIPTION:Title: Inflation and Alternative Early Universe Scenarios in Light of the
Swampland Constraints\nby Robert Brandenberger (McGill University) as
part of Theoretical Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Igor Klebanov (Princeton U.)
DTSTART:20200831T180000Z
DTEND:20200831T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/3
DESCRIPTION:Title: Breaking of Discrete and Continuous Symmetries in Coupled SYK or T
ensor Models\nby Igor Klebanov (Princeton U.) as part of Theoretical P
hysics Seminars (Kentucky)\n\n\nAbstract\nAbstract : \n\nA large number of
Majorana fermions with interactions coupling four of them at a time can e
xhibit interesting quantum dynamics. Models of this kind include the Sachd
ev-Ye-Kitaev (SYK) model\, where the coefficients of quartic interactions
are randomly distributed\, and the Tensor models\, where they respect cont
inuous symmetries. These models exhibit approximate invariance under scali
ng of the time and have power law fall-off of the correlation functions.\n
\nIn this talk we will discuss a pair of SYK or Tensor models coupled by t
he quartic interactions\, and show that they produce a richer set of pheno
mena. These include a line of fixed points\, where critical exponents vary
along the line and formally acquire imaginary parts outside it. For one s
ign of the coupling constant\, the approximate scale invariance continues
to hold. For the other\, a gap opens in the energy spectrum\, resulting in
exponential fall-off of correlation functions. This is indicative of brea
king of a discrete symmetry. Thus\, our quantum mechanical model exhibits
dynamical phenomena characteristic of higher dimensional quantum field the
ories. Furthermore\, the gapped phase of our model may be dual to a certai
n traversable wormhole in two-dimensional space-time.\n\nThe talk will end
with a similar discussion of a pair of complex SYK models coupled by a qu
artic interaction which preserves the U(1) x U(1) symmetry. For a range of
parameters\, this model gives rise to breaking of one of the U(1) symmetr
ies. This is demonstrated via an analysis of the large N Dyson-Schwinger e
quations\, as well as by Exact Diagonalizations of the finite N Hamiltonia
ns.\n\nZoom: https://uky.zoom.us/j/97553578130\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diptarka Das (IIT Kanpur)
DTSTART:20200909T160000Z
DTEND:20200909T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/4
DESCRIPTION:Title: Virasoro blocks and quasimodular forms\nby Diptarka Das (IIT K
anpur) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nW
e analyse Virasoro blocks as an expansion in heavy exchange dimension. For
the one point torus block and the four point sphere block each order in t
he expansion can be written as polynomials in the Eisenstein series. These
polynomials are further constrained to satisfy a recursion relation\, whi
ch can be re-expressed as a noiseless KPZ equation for the blocks. This st
ructure can be utilized along with the Zamolodchikov recursions to develop
an algorithm to construct blocks in the heavy regime. We apply our result
s to find the corrections to averaged heavy-heavy-light OPE coefficients.\
n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Partha Mukhopadhyay (Matscience)
DTSTART:20200916T160000Z
DTEND:20200916T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/5
DESCRIPTION:Title: A Covariant Lattice and its Application to String Bits\nby Par
tha Mukhopadhyay (Matscience) as part of Theoretical Physics Seminars (Ken
tucky)\n\n\nAbstract\nWe explore a possibility of constructing lattice the
ories from a basic principle where lattice is viewed as a restriction of t
he continuum. This allows us to derive a discrete derivative\, nonlocal on
the lattice\, that satisfies Liebniz rule. As a result a theorem related
to locality follows which states that any local equation in the classical
continuum theory holds true also locally on the lattice. Using this one is
able to preserve a remnant of all the global and gauge symmetries\, which
\, in two dimensions\, can be lifted to include local diffeomorphism and W
eyl symmetries as well. Consequently\, one is able\, for example\, to carr
y out classical BRST construction of covariant sting bits (for the first t
ime).\n\nThis lattice derivative is\, in some sense\, similar to SLAC deri
vative discussed earlier in the literature. However\, we point out that it
s action suffers from branch cut ambiguities while acting on Fourier basis
. This may indicate that quantization is not straightforward and may have
to be done entirely in position space.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Maloney (McGill University)
DTSTART:20200928T180000Z
DTEND:20200928T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/6
DESCRIPTION:Title: Gravity from Averaging CFTs\nby Alexander Maloney (McGill Univ
ersity) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\n
I will explore the idea that certain theories of gravity in Anti-de\nSitte
r space are dual to an average over an ensemble of quantum\ntheories\, rat
her than to a specific quantum theory. I will describe\nan average over N
arain’s family of two-dimensional conformal field\ntheories which descri
be free bosons on a torus\, and compute the\npartition function using the
Siegel-Weil formula. The result takes\nthe form of a sum over geometries
as one would expect in a theory of\ngravity. But the gravitational theory
looks more like a Chern-Simons\ntheory than like Einstein gravity.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sabrina Pasterski (Princeton University)
DTSTART:20200930T163000Z
DTEND:20200930T173000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/7
DESCRIPTION:Title: Asymptotic Symmetries & Celestial CFT\nby Sabrina Pasterski (P
rinceton University) as part of Theoretical Physics Seminars (Kentucky)\n\
n\nAbstract\nA universal relationship between asymptotic symmetries\, QFT
soft theorems\, and low energy observables has reinvigorated attempts at f
lat space holography. In this talk we introduce a map from 4d S-matrix el
ements to 2d correlators in the putative dual Celestial CFT. In particula
r\, we will focus on recent progress towards understanding elements of the
IR triangle from the perspective of our Celestial CFT.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Petr Horava (Berkeley)
DTSTART:20201005T180000Z
DTEND:20201005T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/8
DESCRIPTION:Title: Large N Expansion and Strings Out of Equilibrium\nby Petr Hora
va (Berkeley) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbst
ract\nWe use the methods of large N expansion in non-equilibrium many-body
systems with matrix degrees of freedom\, to identify some universal featu
res of the anticipated dual description in terms of non-equilibrium string
perturbation theory. We find that string worldsheets exhibit a triple de
composition\, associated with the forward and backward branches of the Sch
winger-Keldysh time contour\, and with the point at the "end of time" wher
e the two branches meet.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Natalie Klco (U. Washington)
DTSTART:20201012T180000Z
DTEND:20201012T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/9
DESCRIPTION:Title: Calculating Nature Naturally\nby Natalie Klco (U. Washington)
as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nStudying
nature directly from fundamental degrees of freedom is often computationa
lly limited by \nphysical characteristics of exponentially growing configu
ration (Hilbert) spaces with particle number \nand signal-to-noise problem
s. This leaves many systems of interest to nuclear and particle physics \n
intractable for known algorithms with current and foreseeable classical co
mputational resources. By \nleveraging their natural capacity to describe
entangled many-body states\, the use of quantum systems \nthemselves to fo
rm a computational framework is envisioned to be advantageous. In this ta
lk\, I will \nshare a developing perspective on the entanglement structure
of quantum fields and discuss implications \nfor their efficient simulati
on on quantum computational architectures.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ying Zhao (IAS)
DTSTART:20201014T160000Z
DTEND:20201014T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/10
DESCRIPTION:Title: The complexity of Petz map\nby Ying Zhao (IAS) as part of The
oretical Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yoshitaka Hatta
DTSTART:20201019T180000Z
DTEND:20201019T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/11
DESCRIPTION:Title: QCD trace anomaly and the proton mass problem\nby Yoshitaka H
atta as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nThe
trace anomaly of QCD is fundamentally important as it imparts mass to had
rons and nuclei\, hence to the visible universe. In this talk\, I will int
roduce two recent developments regarding the anomaly. In the first part\,
I discuss the decomposition of the trace anomaly into the quark and gluon
parts. This is a well-defined field theoretical problem that can be addres
sed in perturbation theory. In the second part\, I will explain how to mea
sure the gluon condensate $\\lange P|F^{\\mu\\nu}F_{\\mu\\nu}|P\\rangle$\,
which constitutes the major part of the trace anomaly\, in near-threshold
$J/\\psi$ production in electron-proton scattering. After giving a review
of the existing theoretical approaches and the experimental situation\, I
will explain our new approaches to both photo-production and lepto-produc
tion.\n\nPlease email allicsiva@uky.edu for zoom info if interested in att
ending\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lampros Lamprou (MIT)
DTSTART:20201021T160000Z
DTEND:20201021T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/12
DESCRIPTION:Title: Inside the Hologram: The bulk observer's experience\nby Lampr
os Lamprou (MIT) as part of Theoretical Physics Seminars (Kentucky)\n\n\nA
bstract\nI will present a holographic framework for reconstructing the exp
erience of bulk observers in AdS/CFT. In particular\, I will show how to r
ecover the proper time and energy distribution measured along bulk worldli
nes\, directly in the CFT via a universal\, background-independent prescri
ption. For an observer falling into an eternal AdS black hole\, the propos
al resolves a conceptual puzzle raised by Marolf and Wall. Notably\, the p
rescription does not rely on an external dynamical Hamiltonian or the AdS
boundary conditions and is\, therefore\, outlining a general framework for
the emergence of time.\n\nPlease email allicsiva@uky.edu for zoom info if
interested in attending\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michal P. Heller (Max Planck Institute for Gravitational Physics)
DTSTART:20201026T180000Z
DTEND:20201026T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/13
DESCRIPTION:Title: Complexity and Conformal Field Theory\nby Michal P. Heller (M
ax Planck Institute for Gravitational Physics) as part of Theoretical Phys
ics Seminars (Kentucky)\n\n\nAbstract\nViewing fundamental physics process
es through the lenses of quantum information storage and processing is a n
ew frontier in gravity and quantum field theory. Much of what we have lear
nt in the past decade builds on the notion of entanglement and its entropy
. The latter quantifies how hard it is to store a quantum-many body state
of interest on a classical computer. Complexity is a new player in the hig
h-energy physics context and quantifies how hard it is to prepare a quantu
m-many body state using limited resources. Learning from the success story
of entanglement entropy\, establishing universal results on complexity in
two-dimensional conformal field theories should open many new research di
rections\, including finding a precise gravity dual. I will discuss recent
progress on this problem reported in 2005.02415 and 2007.11555 with Flory
.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emil Martinec (University of Chicago)
DTSTART:20201028T160000Z
DTEND:20201028T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/14
DESCRIPTION:Title: The Return of the String\nby Emil Martinec (University of Chi
cago) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nTw
o applications of worldsheet string theory illustrate the structure of str
ing theory near the threshold of black hole formation. In the first\, we
consider string probes of horizonless microstate geometries and find that
strong tidal forces cause infalling strings to become trapped\, mimicking
the absorptive properties of black holes. In the second\, we re-examine t
he structure of (near) BPS microstates and find a mechanism whereby the ge
ometrical description breaks down.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mark Van Raamsdonk (UBC)
DTSTART:20201102T190000Z
DTEND:20201102T200000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/15
DESCRIPTION:Title: Towards Microscopic Models of Big Bang Cosmology\nby Mark Van
Raamsdonk (UBC) as part of Theoretical Physics Seminars (Kentucky)\n\n\nA
bstract\nIn this talk\, we review an approach to describing cosmological\n
physics using ordinary AdS/CFT\, where the cosmological physics is the\nef
fective description of an end-of-the-world brane which cuts off the\nsecon
d asymptotic region of a two-sided black hole. The worldvolume\ngeometry o
f the brane is an FRW big-bang/big-crunch spacetime. In\nfavorable circums
tances\, the brane acts as a Randall-Sundrum Planck\nbrane so that gravity
localizes. We describe a microscopic construction\nfor such an end-of-the
-world brane with localized gravity in AdS/CFT\,\nstarting from N=4 SYM th
eory. We suggest specific microscopic states of\nN=4 SYM theory that may e
ncode the physics in a four-dimensional\ncosmological spacetime.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vishnu Jejjala
DTSTART:20201104T170000Z
DTEND:20201104T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/16
DESCRIPTION:Title: Machine learning as a discovery tool in hep-th\nby Vishnu Jej
jala as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nMac
hine learning provides a new tool for analyzing Big Data and Small Data in
mathematics and theoretical physics. In this talk\, I discuss two case st
udies. The first predicts the volume of the knot complement of hyperbolic
knots from the Jones polynomial. The second predicts the masses of baryons
such as the proton and neutron from knowledge only of the meson spectrum
and distinguishes between different composition hypotheses for exotic QCD
resonances. Both investigations point to the existence of new analytic for
mulae.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Al Shapere (Kentucky)
DTSTART:20201109T190000Z
DTEND:20201109T200000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/17
DESCRIPTION:Title: Quantum Codes and Conformal Field Theories\nby Al Shapere (Ke
ntucky) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\n
There is a rich web of connections between classical error-correcting code
s\, Euclidean lattices\, and chiral conformal field theories. I will expl
ain an analogous relationship between quantum error-correcting codes\, Lor
entzian lattices\, and nonchiral CFTs arising from toroidal compactificati
ons of strings. Specifically\, I will show how quantum stabilizer codes a
re embedded in the operator algebras of associated Narain CFTs. With res
pect to “code” CFTs\, the constraints of modular invariance reduce to
simple algebraic equations. Solving these equations provides many example
s of physically distinct CFTs with the same spectrum\; we also find many s
olutions that do not correspond to any code CFT\, and likely do not corres
pond to any CFT at all. This exposes a crucial limitation of the conforma
l bootstrap program – that in general\, a solution of the bootstrap equa
tions implies neither the existence nor the uniqueness of a corresponding
CFT.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Raul Briceno (JLab)
DTSTART:20201111T170000Z
DTEND:20201111T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/19
DESCRIPTION:Title: Long Range Processes in QCD\nby Raul Briceno (JLab) as part o
f Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nA rich variety of
phenomena in the Standard Model and its extensions manifest in long-range
processes involving bound states of quantum chromodynamics (QCD)\, namely
hadrons. These are processes where intermediate hadronic states propagate
over a long distance\, between electroweak interactions. Examples include
virtual Compton scattering and double-beta decay. Such processes are at t
he cusp of what can be systematically studied given two challenges. First\
, these reactions involve hadrons\, and as a result one must use a non-per
turbative tool to access their amplitudes. Currently lattice QCD is the on
ly systematically improvable way we have for doing just this. Second\, lat
tice QCD is defined in a finite\, Euclidean spacetime. This introduces its
own specific challenges\, time in purely imaginary in lattice QCD\, and b
y truncating the space one looses the notion of asymptotic states. In this
talk I explain how these issues can all be resolved systematically for a
relatively large kinematic region. In presenting the necessary formalism f
or doing this\, I will summarize recent progress in lattice QCD in order t
o argue that the community is up to the challenge.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Barthel (Duke)
DTSTART:20201116T190000Z
DTEND:20201116T200000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/20
DESCRIPTION:Title: Entanglement entropy of energy eigenstates follows a universal sc
aling function\nby Thomas Barthel (Duke) as part of Theoretical Physic
s Seminars (Kentucky)\n\n\nAbstract\nWe consider the entanglement entropie
s of energy eigenstates in quantum many-\nbody systems. For the typical mo
dels that allow for a field-theoretical\ndescription of the long-range phy
sics\, we find that the entanglement entropy of\n(almost) all eigenstates
is described by a single scaling function. This is\npredicated on the vali
dity of the weak or strong eigenstate thermalization\nhypothesis (ETH)\, w
hich then implies that the scaling functions can be deduced\nfrom subsyste
m entropies of thermal ensembles. The scaling functions describe\nthe full
crossover from the groundstate entanglement regime for low energies\nand
small subsystem size (area or log-area law) to the extensive volume-law\nr
egime for high energies or large subsystem size. For critical 1d systems\,
the\nscaling function follows from conformal field theory (CFT). We use i
t to also\ndeduce the scaling function for Fermi liquids in d>1 dimensions
. These\nanalytical results are complemented by numerics for large non-int
eracting\nsystems of fermions in d=1\,2\,3 and the harmonic lattice model
in d=1\,2.\nLastly\, we demonstrate ETH for entanglement entropies and the
validity of the\nscaling arguments in integrable and non-integrable inter
acting spin chains. In\nparticular\, we analyze the XXZ and transverse-fie
ld Ising models with and\nwithout next-nearest-neighbor interactions.\n\nR
eferences: arXiv:1905.07760\, arXiv:1912.10045\, arXiv:2010.07265\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robert De Mello Koch (U. of Witwatersrand)
DTSTART:20210127T170000Z
DTEND:20210127T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/21
DESCRIPTION:Title: Scrambling in Yang-Mills Theory\nby Robert De Mello Koch (U.
of Witwatersrand) as part of Theoretical Physics Seminars (Kentucky)\n\n\n
Abstract\nWe study operators with a bare dimension that grows as N^2 in th
e large N limit. These operators are labeled by a Young diagram with p lon
g rows\, as well as a graph\, with p nodes. The dilatation operator descri
bing the mixing of these operators defines a Hamiltonian for excitations h
opping on this graph. The scrambling and equilibration of the resulting dy
namics is studied.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Samir Mathur (OSU)
DTSTART:20210125T190000Z
DTEND:20210125T200000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/22
DESCRIPTION:by Samir Mathur (OSU) as part of Theoretical Physics Seminars
(Kentucky)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sean Hartnoll (Stanford)
DTSTART:20210426T180000Z
DTEND:20210426T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/24
DESCRIPTION:Title: The classical interior of black holes in holography\nby Sean
Hartnoll (Stanford) as part of Theoretical Physics Seminars (Kentucky)\n\n
\nAbstract\nThe exterior dynamics of black holes has played a major role\n
in holographic duality\, describing the approach to thermal equilibrium\no
f strongly coupled media. The interior dynamics of black holes in a\nholog
raphic setting has\, in contrast\, been largely unexplored. I will\ndescri
be recent work investigating the classical interior dynamics of\nvarious h
olographic black holes. I will discuss the nature of the\nsingularity\, th
e absence of Cauchy horizons and a new kind of chaotic\nbehavior that emer
ges in the presence of charged scalar fields.\n\nPassword: Theory\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anatoli Polkovnikov (Boston U.)
DTSTART:20210208T190000Z
DTEND:20210208T200000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/26
DESCRIPTION:Title: Quantum eigenstates from classical Gibbs distributions\nby An
atoli Polkovnikov (Boston U.) as part of Theoretical Physics Seminars (Ken
tucky)\n\n\nAbstract\nI will discuss how the language of wave functions (s
tate vectors) and associated non-commuting Hermitian operators naturally e
merges from classical mechanics by applying the inverse Wigner-Weyl transf
orm to the phase space probability distribution and observables. In this l
anguage\, the Schrödinger equation follows from the Liouville equation\,
with ℏ now a free parameter. Classical stationary distributions can be r
epresented as sums over stationary states with discrete (quantized) energi
es\, where these states directly correspond to quantum eigenstates. Intere
stingly\, it is now classical mechanics which allows for apparent negative
probabilities to occupy eigenstates. This correspondence is particularly
pronounced for canonical Gibbs ensembles\, where classical eigenstates sat
isfy an integral eigenvalue equation that reduces to the Schrödinger equa
tion in a saddle-point approximation controlled by the inverse temperature
. This correspondence by showing that some paradigmatic examples such as t
unneling\, band structures\, Berry phases\, Landau levels\, level statisti
cs and quantum eigenstates in chaotic potentials can be reproduced to a su
rprising precision from a classical Gibbs ensemble\, without any reference
to quantum mechanics. At the end I will mention some unpublished results
on emergence of negative probabilities and associated doubling of the Hilb
ert space\, which is similar to emergence of spin degrees of freedom.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Soumyadeep Chaudhuri (Hebrew U.)
DTSTART:20210203T170000Z
DTEND:20210203T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/27
DESCRIPTION:Title: Thermal order in large N conformal gauge theories\nby Soumyad
eep Chaudhuri (Hebrew U.) as part of Theoretical Physics Seminars (Kentuck
y)\n\n\nAbstract\nOur experience with many physical systems tells us that
usually when a symmetry is spontaneously broken at low temperatures\, it i
s restored upon increasing the temperature sufficiently. The abundance of
such systems raises the question of whether this is a universal feature o
f all quantum systems. In this talk\, I will present examples of (3+1)-dim
ensional non-supersymmetric large N gauge theories which demonstrate viola
tions of the above feature. I will argue that in the N tending to infinity
limit\, these theories have conformal manifolds which survive under all l
oop corrections to the beta functions of the couplings. I will show that u
nder certain conditions\, a subset of points on such a conformal manifold
demonstrates the spontaneous breaking of a global symmetry at all nonzero
temperatures. Furthermore\, I will demonstrate that this symmetry breaking
is accompanied by the Higgsing of a subset of gauge bosons leading the sy
stem to be in a persistent Brout-Englert-Higgs phase.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roberto Emparan (U. of Barcelona)
DTSTART:20210210T170000Z
DTEND:20210210T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/28
DESCRIPTION:Title: Quantum BTZ black hole\nby Roberto Emparan (U. of Barcelona)
as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nThe stud
y of quantum effects on black holes including their gravitational backreac
tion is an important but notoriously hard problem. I will begin by reviewi
ng how the framework of braneworld holography allows to solve it for stron
gly-coupled quantum conformal fields. Then I will describe a holographic c
onstruction of quantum rotating BTZ black holes (quBTZ) using an exact dua
l four-dimensional bulk solution. Besides yielding the quantum-corrected g
eometry and the renormalized stress tensor of quBTZ\, we use it to show th
at the quantum black hole entropy\, which includes the entanglement of the
fields outside the horizon\, rather non-trivially satisfies the first law
of thermodynamics\, while the Bekenstein-Hawking-Wald entropy does not.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ramis Movassagh (MIT-IBM)
DTSTART:20210217T170000Z
DTEND:20210217T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/29
DESCRIPTION:Title: Constructing quantum codes from any classical code and their embe
dding in ground space of local Hamiltonians\nby Ramis Movassagh (MIT-I
BM) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nWe i
ntroduce a framework for constructing a quantum error correcting code from
any classical error correcting code. This includes CSS codes and goes bey
ond the stabilizer formalism to allow quantum codes to be constructed from
classical codes that are not necessarily linear or self-orthogonal. We gi
ve an algorithm that explicitly constructs quantum codes with linear dista
nce and constant rate from classical codes with a linear distance and rate
. As illustrations for small size codes\, we obtain Steane's 7−qubit cod
e uniquely from Hamming's [7\,4\,3] code\, and obtain other error detectin
g quantum codes from other explicit classical codes of length 4 and 6. Mot
ivated by quantum LDPC codes and the use of physics to protect quantum inf
ormation\, we introduce a new 2-local frustration free quantum spin chain
Hamiltonian whose ground space we analytically characterize completely. By
mapping classical codewords to basis states of the ground space\, we util
ize our framework to demonstrate that the ground space contains explicit q
uantum codes with linear distance. This side-steps the Bravyi-Terhal no-go
theorem because our work allows for more general quantum codes beyond the
stabilizer and/or linear codes. We hesitate to call this an example of {\
\it subspace} quantum LDPC code with linear distance.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aninda Sinha (IISc\, Bangalore)
DTSTART:20210224T143000Z
DTEND:20210224T153000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/30
DESCRIPTION:Title: Crossing symmetric dispersion relations in QFTs and CFTs\nby
Aninda Sinha (IISc\, Bangalore) as part of Theoretical Physics Seminars (K
entucky)\n\n\nAbstract\nI will discuss crossing symmetric dispersion relat
ions in QFTs and CFTs. I will talk about connections with Polyakov’s 197
4 work\, the crossing symmetric Polyakov-Mellin bootstrap\, and connection
s with fixed-t dispersion relations. I will also talk about generalized Fr
oissart bounds in QFTs which follow from this approach.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ismail Zahed (SUNY\, Stony Brook)
DTSTART:20210222T190000Z
DTEND:20210222T200000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/31
DESCRIPTION:Title: Reggeized scattering\, entanglement and chaos using AdS/CFT\n
by Ismail Zahed (SUNY\, Stony Brook) as part of Theoretical Physics Semina
rs (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Greg Kaplanek (McMaster University)
DTSTART:20210308T190000Z
DTEND:20210308T200000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/32
DESCRIPTION:Title: Hot qubits on the horizon\nby Greg Kaplanek (McMaster Univers
ity) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nPer
turbation theory for gravitating quantum systems tends to\nfail at very la
te times (a type of perturbative breakdown known as\nsecular growth). We a
rgue that gravity is best treated as a\nmedium/environment in such situati
ons\, where reliable late-time\npredictions can be made using tools borrow
ed from quantum optics. To\nshow how this works\, we study the explicit ex
ample of a qubit hovering\njust outside the event horizon of a Schwarzschi
ld black hole (coupled to\na real scalar field) and reliably extract the l
ate-time behaviour for\nthe qubit state. At very late times\, the so-calle
d Unruh-DeWitt detector\nis shown to asymptote to a thermal state at the H
awking temperature.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shai Chester (Weizmann Institute)
DTSTART:20210310T170000Z
DTEND:20210310T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/33
DESCRIPTION:Title: Derivation of AdS/CFT for Vector Models\nby Shai Chester (Wei
zmann Institute) as part of Theoretical Physics Seminars (Kentucky)\n\n\nA
bstract\nWe derive an explicit map between the singlet sector of the free
and critical O(N) and U(N) vector models in any spacetime dimension above
two and to all orders in 1/N\, and a bulk higher spin theory in anti-de Si
tter space in one higher dimension. For the boundary theory\, we use the b
ilocal formalism of Jevicki et al to restrict to the singlet sector of the
vector model. The bulk theory is defined from the boundary theory via our
mapping and is a consistent quantum higher spin theory with a well define
d action. Our mapping relates bilocal operators in the boundary theory to
higher spin fields in the bulk\, while single trace local operators in the
boundary theory are related to boundary values of higher spin fields.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Toby Wiseman (Imperial College\, London)
DTSTART:20210315T180000Z
DTEND:20210315T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/34
DESCRIPTION:Title: Quantum black holes on the lattice\nby Toby Wiseman (Imperial
College\, London) as part of Theoretical Physics Seminars (Kentucky)\n\n\
nAbstract\nHolography apparently relates certain quantum field theories to
quantum\ntheories of gravity. The original instance of this is Maldacena'
s\nduality between maximally supersymmetric gauge theories and type II\nst
ring theory in the presence of D-branes. In the ’t Hooft limit\, and at\
nappropriate temperatures\, the dual to the gauge theory is described by\n
certain black holes (or rather black p-branes). This allows the\nremarkabl
e opportunity to perform calculations of quantum black holes\nthrough the
equivalent gauge theory\, and to check the consistency of\nholographic dua
lity. I will discuss such calculations\, and the progress\nthat has been m
ade over the last decade in showing that the predicted\ngravity behaviour
does indeed emerge from thermal gauge theory.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pranjal Nayak (U. of Geneva)
DTSTART:20210324T160000Z
DTEND:20210324T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/35
DESCRIPTION:Title: Quantum ergodicity and Euclidean Wormholes\nby Pranjal Nayak
(U. of Geneva) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbs
tract\nFor a generic quantum-many-body system\, quantum ergodicity is defi
ned as the limit in which the spectrum of the system resembles that of a r
andom matrix theory (RMT) in the corresponding symmetry class. In this tal
k I will describe the correlation functions in the ergodic limit\, making
use of the causal symmetry breaking to construct an EFT describing the rel
evant universal late-time dynamics: the ramp and the plateau. I will also
discuss the bulk interpretation of these results in terms of Euclidean wor
mholes.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nabil Iqbal (Durham U.)
DTSTART:20210329T180000Z
DTEND:20210329T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/36
DESCRIPTION:Title: Mean string field theory\nby Nabil Iqbal (Durham U.) as part
of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nJust as conventi
onal global symmetries result in a conserved particle number\, higher-form
global symmetries are associated with a conserved density of higher dimen
sional objects\, such as strings or branes. Many well-known systems posses
s such symmetries. I will present an overview of the applications of such
symmetries and discuss the prospect of using them to enlarge the usual Lan
dau classification of the phases of matter. I will then describe the const
ruction of a continuum Landau-Ginzburg theory to describe the spontaneous
breaking of a higher-form symmetry. As the order parameter is an operator
that creates a string\, the framework can be thought of as a kind of "mean
string field theory" that provides a non-perturbative description where e
ffective strings can be created and destroyed. I will argue that many aspe
cts of higher form symmetries — including the phase structure\, the beha
vior of line operators\, and the dynamics of Goldstone modes — can be tr
ansparently understood in this framework.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dan Carney (UMIACS)
DTSTART:20210412T180000Z
DTEND:20210412T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/37
DESCRIPTION:Title: Quantum limits to measurement and dark matter detection\nby D
an Carney (UMIACS) as part of Theoretical Physics Seminars (Kentucky)\n\n\
nAbstract\nIf dark matter exists\, the only way it is guaranteed to couple
to visible matter is through gravity. Trying to directly detect dark matt
er in a terrestrial laboratory through this coupling would be very difficu
lt due to the weakness of gravity. However\, it has recently been suggeste
d that an array of quantum-limited mechanical sensors could be constructed
to detect heavy (roughly Planck-scale) dark matter candidates purely via
gravity. I'll review the basic idea\, some applications to other (non-grav
itational) dark matter detection\, and some current experimental work.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stanley Brodsky (SLAC)
DTSTART:20210419T180000Z
DTEND:20210419T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/38
DESCRIPTION:Title: Color Confinement and Supersymmetric Features of Hadron Physics f
rom Light-Front Holography\nby Stanley Brodsky (SLAC) as part of Theor
etical Physics Seminars (Kentucky)\n\n\nAbstract\nI will review applicatio
ns of superconformal algebra\, light-front holography\, and an extended fo
rm of conformal symmetry to hadron spectroscopy and dynamics. QCD is not
supersymmetrical in the traditional sense -- the QCD Lagrangian is based o
n quark and gluonic fields -- not squarks nor gluinos. However\, its hadro
nic eigensolutions conform to a representation of superconformal algebra\,
reflecting the underlying conformal symmetry of chiral QCD. The eigensolu
tions of superconformal algebra provide a unified Regge spectroscopy of me
son\, baryon\, and tetraquarks of the same parity and twist as equal-mass
members of the same 4-plet representation with a universal Regge slope. Th
e pion $q \\bar q$ eigenstate is composite but yet has zero mass for $m_q=
0.$ Light-Front Holography also predicts the form of the nonperturbative
QCD running coupling: $\\alpha_s(Q^2) \\propto \\exp{-{Q^2/4 \\kappa^2}}$
\, in agreement with the effective charge determined from measurements o
f the Bjorken sum rule. One also obtains viable predictions for tests of
hadron dynamics such as spacelike and timelike hadronic form factors\, str
ucture functions\, distribution amplitudes\, and transverse momentum distr
ibutions. The combined approach of light-front holography and superconform
al algebra also provides insight into the origin of the QCD mass scale and
color confinement.\n\nPassword: Theory\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arjun Kar (UBC)
DTSTART:20210331T160000Z
DTEND:20210331T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/39
DESCRIPTION:Title: A hierarchy of complexity growth from integrability and chaos
\nby Arjun Kar (UBC) as part of Theoretical Physics Seminars (Kentucky)\n\
n\nAbstract\nQuantum complexity has been conjectured to be relevant for bl
ack hole interiors. In particular\, Susskind has conjectured a generic fo
rm of complexity growth and saturation for maximally chaotic systems like
black holes. Using geodesic complexity techniques\, we study the complexi
ty of time evolution in free\, integrable\, and chaotic systems with N deg
rees of freedom. We demonstrate that the growth rate of this complexity i
s related to more familiar properties of physical theories like 1) the exi
stence of creation/annihilation operators and 2) smeared thermal two-point
functions. Using these properties\, we find that the complexity saturate
s in free\, integrable\, and chaotic theories at time scales which are on
the order of N^{1/2}\, polynomial in N\, and exponential in N\, respective
ly. Our results in the free theory improve an existing bound in the compl
exity theory literature\, and our results in chaotic theories are based on
ly on coarse properties of the spectrum and eigenstates.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Victor Gorbenko
DTSTART:20210407T160000Z
DTEND:20210407T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/40
DESCRIPTION:Title: On QFT in de Sitter\nby Victor Gorbenko as part of Theoretica
l Physics Seminars (Kentucky)\n\n\nAbstract\nI will discuss the tools we a
re developing to calculate correlation functions of primordial inflationar
y perturbations. In this talk we will focus on the limit where gravitation
al excitations are neglected and the cosmological spacetime is assumed to
be exactly de Sitter. Even in this simplifying limit\, which corresponds t
o a Quantum Field Theory on a de Sitter background\, very few examples of
explicit analytic calculations exist and little is known about basic prope
rties of the correlators. I will show that for any dS QFT there exists a t
heory formulated in a Euclidean Anti-de SItter space and which reproduces
all the correlation functions. This leads to major technical simplificatio
ns and allows to demonstrate various analytic properties of the cosmologic
al observables. Understanding of these properties has both phenomenologica
l applications in inflation\, as well as provides some hints about more fu
ndamental description for cosmological spacetimes.\n\nPasscode\, if needed
: 103620\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrei Alexandru
DTSTART:20210428T160000Z
DTEND:20210428T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/41
DESCRIPTION:Title: Quantum computing for bosonic fields\nby Andrei Alexandru as
part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nAs universa
l quantum computers move from theoretical devices towards concrete\nrealiz
ations\, albeit still quite experimental\, there is a lot of interest in\n
understanding whether outstanding problems in nuclear physics\, like real-
time\ndynamics and bulk properties of nuclear matter\, could be solved usi
ng these \nmachines. For these applications we need to represent in hardwa
re quantum field \ntheories for both fermionic and bosonics degrees of fre
edom. Discretized fermionic \nfields can be represented fully since they m
ap naturally onto qbits. On the other \nhand bosonic degrees of freedom--w
hich even for discretized fields require an \ninfinite dimensional Hilbert
space at each site--require a truncation. In this \ntalk I discuss two di
rections we investigated to address this problem: using \ndiscrete subsets
to represent gauge degrees of freedom\, or truncations in a dual \nspace
that that preserve the original symmetries of the theory. As test-cases \n
for these ideas we use pure-gauge QCD and the sigma-model.\n\nPassword: 14
6625\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Masanori Hanada (Surrey U.)
DTSTART:20210414T160000Z
DTEND:20210414T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/42
DESCRIPTION:Title: Large-N limit as a second quantization\nby Masanori Hanada (S
urrey U.) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract
\nIn gauge/gravity duality\, the information regarding the gravitational g
eometry (e.g.\, black hole and smooth exterior geometry) has to be encoded
in gauge theory. Clearly\, the color degrees of freedom (matrix degrees o
f freedom) should play the key role\, because the duality can hold even wh
en the gauge theory side is a matrix model. In this talk\, I will suggest
a simple way of encoding the geometry to matrices\, along the line of Witt
en's work on the effective action of D-branes and strings\, and the Matrix
Theory conjecture by Banks\, Fischler\, Shenker and Susskind. Roughly spe
aking\, eigenvalues of matrices 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 against such simple interpretation advocated by Polch
inski in 1998. His argument used generic properties of large-N gauge theor
y to show that the ground-state wave function delocalizes at large N\, lea
ding to a conflict with the locality in the bulk geometry. We show that th
is argument is not correct: the ground-state wave function does not deloca
lize\, and there is no conflict with the locality of the bulk geometry. In
order to understand how the old argument fails\, recently-discovered conn
ection between color confinement and Bose-Einstein condensation is useful.
This confinement-BEC connection has a striking consequence: in the SU(N)
gauge theory\, there is a partially-deconfined phase in which an SU(M)-sub
group is deconfined. Partial deconfinement\, combined with the "eigenvalue
= location" picture\, provides us with a natural scenario to realize the
idea in BFSS Matrix Theory conjecture --- extended objects\, such as black
hole\, are realized as bound states of D-branes and strings\, that look l
ike non-commutative blocks in big matrices --- in the Maldacena-type gauge
/gravity duality. In the large-N limit\, various many-body states can be r
ealized by considering block-diagonal matrix configurations\, similarly to
the BFSS proposal. Therefore\, the large-N limit of gauge theory can be i
nterpreted as the second quantization of the gravity side. \n\nIf time per
mits\, we will discuss how we might be able to check this proposal quantit
atively\, via classical or quantum simulations.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Murat Kologlu (Oxford)
DTSTART:20210421T160000Z
DTEND:20210421T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/43
DESCRIPTION:Title: Holographic correlators at finite temperature\nby Murat Kolog
lu (Oxford) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstra
ct\nWe consider weakly-coupled QFT in AdS at finite temperature. We comput
e the holographic thermal two-point function of scalar operators in the bo
undary theory. We present analytic expressions for leading corrections due
to local quartic interactions in the bulk\, with an arbitrary number of d
erivatives and for any number of spacetime dimensions. The solutions are f
ixed by judiciously picking an ansatz and imposing consistency conditions.
The conditions include analyticity properties\, consistency with the oper
ator product expansion\, and the Kubo-Martin-Schwinger condition. For the
case without any derivatives we show agreement with an explicit diagrammat
ic computation. The structure of the answer is suggestive of a thermal Mel
lin amplitude. Additionally\, we derive a simple dispersion relation for t
hermal two-point functions which reconstructs the function from its discon
tinuity.\n\nPassword: 496169\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Keh-Fei Liu (Kentucky)
DTSTART:20210503T180000Z
DTEND:20210503T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/44
DESCRIPTION:Title: Hadron Cosmological Constant and Parton Degrees of Freedom\nb
y Keh-Fei Liu (Kentucky) as part of Theoretical Physics Seminars (Kentucky
)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Johanna Erdmenger
DTSTART:20210505T160000Z
DTEND:20210505T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/45
DESCRIPTION:Title: Complexity and modular flows: Relating quantum information\, quan
tum field theory and gravity\nby Johanna Erdmenger as part of Theoreti
cal Physics Seminars (Kentucky)\n\n\nAbstract\nI present recent work of ou
r group on realizing computational complexity in conformal field theories
in view of relating it holographically to complexity proposals in AdS grav
ity. Gates and cost functions in the CFT are introduced and used for a com
plexity definition based on geometric actions on Virasoro and Kac-Moody or
bits. We discuss a relation to the Euler-Arnold approach in Hamiltonian dy
namics. In a complementary project\, we developed a new method for evaluat
ing modular flows for 1+1-dimensional chiral fermions\, working directly f
rom the resolvent in complex analysis. Both projects provide new ingredien
ts for exploring the connection between spacetime and entanglement.\n\nTal
k based on 2004.03619 and 2008.07532\n\nPassword: 489528\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shreya Vardhan (MIT)
DTSTART:20210519T160000Z
DTEND:20210519T170000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/46
DESCRIPTION:Title: An equilibrium approximation for quantum-informational observable
s in quantum many-body systems and gravity\nby Shreya Vardhan (MIT) as
part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nI will exp
lain an approximation method that gives a simple universal expression for
the Renyi entropies of an equilibrated pure state in a chaotic quantum man
y-body system. This expression is independent of the details of the initia
l state and hence reflects thermalization\, while also being manifestly co
nsistent with unitarity. I will discuss how applying this method to models
of evaporating black holes leads to a derivation of replica wormholes\, w
hich have recently been used to address the information loss paradox in th
ese models. More generally\, this approach elucidates the role played by E
uclidean path integrals in calculations of time-evolved Renyi entropies. I
t also helps address the question of whether an average over theories is n
eeded in order to explain results from replica wormholes. I will also comm
ent on work in progress on applications of this approximation method to ot
her quantum-informational quantities.\n\nPassword: 801404\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Allic Sivaramakrishnan (Caltech)
DTSTART:20221026T163000Z
DTEND:20221026T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/47
DESCRIPTION:Title: On-shell Correlators and Color-Kinematics Duality in Curved Space
times\nby Allic Sivaramakrishnan (Caltech) as part of Theoretical Phys
ics Seminars (Kentucky)\n\n\nAbstract\nIn this talk\, we present progress
towards generalizing on-shell kinematics and color-kinematics duality to c
urved spacetimes. First\, we define a perturbatively calculable quantity
—the on-shell correlator—which furnishes a unified description of part
icle dynamics in curved spacetime. Specializing to the cases of flat and a
nti-de Sitter space\, on-shell correlators coincide precisely with on-shel
l scattering amplitudes and boundary correlators respectively. We then int
roduce a notion of on-shell kinematics for symmetric spaces in which the c
orresponding on-shell momenta are built from isometry generators. Using th
is isometric language in AdS\, we compute scalar correlators and give a fi
eld-theoretic derivation of color-kinematics duality for the nonlinear sig
ma model. Finally\, we comment on possible extensions to spacetimes withou
t symmetry.\n\nZoom: https://uky.zoom.us/j/86707156638?pwd=VUNFUUl0cmxGMVA
rNXpVTTV1MGQ0QT09\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Scott Collier (Princeton)
DTSTART:20221102T163000Z
DTEND:20221102T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/48
DESCRIPTION:Title: Emergent Averaging in Large-$N$ Holography\nby Scott Collier
(Princeton) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstra
ct\nAbstract: In recent years\, a new holographic paradigm has emerged in
which simple theories of gravity in low dimensions are dual to statistical
ensembles of quantum mechanical systems rather than particular quantum sy
stems. This is a conceptual departure from the conventional holographic pa
radigm\, particularly as realized in string theory. A hallmark of such ave
raged holographic dualities is the non-factorization of multi-boundary obs
ervables due to the presence of Euclidean wormholes in the bulk gravitatio
nal theory. However\, more realistic holographic dualities in higher dimen
sions are not expected to fundamentally involve microscopic averaging. Nev
ertheless\, there are apparently contributions to the semiclassical gravit
ational path integral that are associated with averaging in the boundary t
heory. In this talk I will attempt to reconcile these perspectives by eluc
idating the emergence of averaging in two different models based on recent
works of mine: one top-down\, the other bottom-up. In both cases\, averag
ing of boundary degrees of freedom is an emergent phenomenon associated wi
th the expansion around the semiclassical limit.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tadashi Takayanagi (Kyoto U)
DTSTART:20221104T000000Z
DTEND:20221104T013000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/49
DESCRIPTION:Title: CFT Dual of $dS_3$ and Pseudo Entropy\nby Tadashi Takayanagi
(Kyoto U) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract
\nWe propose a holographic duality for gravity on a three-\ndimensional de
Sitter space. This is essentially given by a $k=-2$ limit\nof SU(2) WZW m
odel. We show that this proposal reproduces the expected\nfree energy in d
e Sitter gravity. We also analyze the geodesic length in\nthe three dimens
ional de Sitter spacetime and argue that it is\ninterpreted as holographic
pseudo entropy. We will also discuss a time-\nlike entanglement entropy i
n AdS/CFT which shares a similar property in\nterms of pseudo entropy.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nima Lashkari (Purdue)
DTSTART:20221111T173000Z
DTEND:20221111T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/50
DESCRIPTION:Title: Exact RG yields cMERA\nby Nima Lashkari (Purdue) as part of T
heoretical Physics Seminars (Kentucky)\n\n\nAbstract\nWe study the exact r
enormalization group (ERG) of the free O(N) vector model using a generaliz
ed smooth regulator that modifies the dispersion relation and suppresses t
he ultraviolet modes. We show that the ERG flow for the wave-functionals l
eads to a unitary flow that includes\, as a special case\, the continuous
multi-scale renormalization (cMERA) network. We discuss tensor network ren
ormalization and the approximate quantum error correction code in RG.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Damian Galante (Kings College (London))
DTSTART:20221116T173000Z
DTEND:20221116T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/51
DESCRIPTION:Title: De Sitter horizons & holography\nby Damian Galante (Kings Col
lege (London)) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbs
tract\nAn inertial observer in de Sitter spacetime is always surrounded by
a cosmological event horizon. This horizon shares some similarities with
the black hole event horizon\, which suggests the idea of using tools from
holography to understand its microscopic nature. In this talk\, I will de
scribe some probes of the cosmological horizon that differ from those of b
lack holes and comment on possible holographic interpretations of such res
ults.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atish Dabholkar (ICTP Trieste)
DTSTART:20221130T170000Z
DTEND:20221130T183000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/52
DESCRIPTION:Title: Quantum Entanglement in String Theory\nby Atish Dabholkar (IC
TP Trieste) as part of Theoretical Physics Seminars (Kentucky)\n\nAbstract
: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Zhiboedov (Harvard)
DTSTART:20220928T163000Z
DTEND:20220928T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/54
DESCRIPTION:Title: Holographic thermal correlators\nby Alexander Zhiboedov (Harv
ard) as part of Theoretical Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sunil Mukhi (IISER (Pune) and IAS)
DTSTART:20221003T163000Z
DTEND:20221003T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/55
DESCRIPTION:Title: Classification of Unitary RCFTs with Two Primaries and c < 25
\nby Sunil Mukhi (IISER (Pune) and IAS) as part of Theoretical Physics Sem
inars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mitch Weaver (Cincinnati)
DTSTART:20221012T163000Z
DTEND:20221012T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/56
DESCRIPTION:Title: Mixing local and extended operators: a 2d vertex algebra in 4d N
= 2 SCFTs\nby Mitch Weaver (Cincinnati) as part of Theoretical Physics
Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Prashant Raman (IISC)
DTSTART:20220921T163000Z
DTEND:20220921T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/57
DESCRIPTION:Title: Celestial insights into the S-matrix bootstrap\nby Prashant R
aman (IISC) as part of Theoretical Physics Seminars (Kentucky)\n\nAbstract
: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Larry Yaffe (U. Washington)
DTSTART:20221031T173000Z
DTEND:20221031T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/58
DESCRIPTION:Title: Higgs/confinement transitions with fundamental representation mat
ter\nby Larry Yaffe (U. Washington) as part of Theoretical Physics Sem
inars (Kentucky)\n\n\nAbstract\nIt has long been known that smooth crossov
ers between “Higgs” regimes and “confining” regimes are possible i
n some gauge theories with fundamental representation matter\, leading to
a notion of Higgs/confinement “complementarity”. But the validity\, o
r otherwise\, of such complementarity can be subtle\, especially in massle
ss phases with Goldstone bosons. This talk will examine the presence or a
bsence of Higgs/confinement phase transitions\, when there are no distingu
ishing local order parameters\, in both instructive models and in dense QC
D.\n\nZoom: https://uky.zoom.us/j/89827733198?pwd=azhrUllxR2xMcDNyanlFMDJ3
bWU3dz09\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:K. Narayan (Chennai Maths Institute)
DTSTART:20230801T190000Z
DTEND:20230801T203000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/59
DESCRIPTION:Title: de Sitter space\, extremal surfaces and time-entanglement\nby
K. Narayan (Chennai Maths Institute) as part of Theoretical Physics Semin
ars (Kentucky)\n\nLecture held in CP 303.\n\nAbstract\nI will describe ext
remal surfaces in de Sitter space anchored at the future boundary I+. Sinc
e such surfaces do not return\, they require extra data or boundary condit
ions in the past (interior). In entirely Lorentzian de Sitter spacetime\,
this leads to future-past timelike surfaces stretching between I±. Apart
from an overall −i factor (relative to spacelike surfaces in AdS) their
areas are real and positive. With a no-boundary type boundary condition\,
the top half of these timelike surfaces joins with a spacelike part on the
hemisphere giving a complex-valued area. Motivated by these\, we describe
two aspects of “time-entanglement” in simple toy models in quantum me
chanics. One is based on a future-past thermofield double type state entan
gling timelike separated states\, which leads to entirely positive structu
res. Another is based on the time evolution operator and reduced transitio
n amplitudes\, which leads to complex-valued entropy. There are close para
llels with pseudo-entropy which we will clarify.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sotaro Sugishita (Yukawa Institute)
DTSTART:20230823T163000Z
DTEND:20230823T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/60
DESCRIPTION:Title: Dress code for infrared safe scattering in QED\nby Sotaro Sug
ishita (Yukawa Institute) as part of Theoretical Physics Seminars (Kentuck
y)\n\nLecture held in CP 303.\n\nAbstract\nWe consider the infrared (IR) a
spects of S-matrix in QED. We will review IR divergences and their relatio
n to the asymptotic symmetry in QED\, and introduce the dressed state form
alism to obtain IR-safe S-matrix elements. We show a generic condition (dr
ess code) for dressed states to obtain IR-safe S-matrix elements\, and exp
lain that the dress code can be interpreted as the memory effect and repre
sents the superselection rule of asymptotic symmetry.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gautam Mandal (TIFR (Mumbai))
DTSTART:20230821T180000Z
DTEND:20230821T193000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/61
DESCRIPTION:Title: A fresh look at the large-N limit of matrix models and holography
\nby Gautam Mandal (TIFR (Mumbai)) as part of Theoretical Physics Semi
nars (Kentucky)\n\nLecture held in CP 303.\n\nAbstract\nWe will discuss so
me known subtleties of emergent geometries from large N theories (why they
are different from our normal expectation for a continuum spacetime) and
discuss a way to address them. We will use matrix models as our main examp
le. The primary tool will be an exact bosonization of nonrelativistic ferm
ions that was discovered some time ago.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Spenta Wadia (ICTS-TIFR (Bengalaru))
DTSTART:20230816T163000Z
DTEND:20230816T180000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/63
DESCRIPTION:Title: Dynamics of Black Hole Evaporation in 2-dim Gravity\nby Spent
a Wadia (ICTS-TIFR (Bengalaru)) as part of Theoretical Physics Seminars (K
entucky)\n\nLecture held in CP 303.\n\nAbstract\nWe will discuss the non-e
quilibrium dynamics of a 2-dim black hole coupled to an external bath\, us
ing the Schwinger-Keldysh formalism. Tracing the evaporation in real time
amounts to solving non-local stochastic differential equations for the BH
degrees of freedom. We describe the fluctuations that characterise the end
point of the evaporation process. This talk is based on arXiv:2210.15579.
\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lorenz Eberhardt (U. Amsterdam)
DTSTART:20231018T173000Z
DTEND:20231018T183000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/64
DESCRIPTION:Title: The Virasoro Minimal String\nby Lorenz Eberhardt (U. Amsterda
m) as part of Theoretical Physics Seminars (Kentucky)\n\nLecture held in C
P 303.\n\nAbstract\nI will introduce a critical string theory in two dimen
sions and demonstrate that this theory\, viewed as two-dimensional quantum
gravity on the worldsheet\, is equivalent to a double-scaled matrix integ
ral\, which provides the holographic description. The worldsheet theory co
nsists of Liouville CFT with central charge c\\ge 25 coupled to timelike L
iouville CFT with central charge 26-c. The double-scaled matrix integral h
as as its leading density of states the universal Cardy density of primari
es in a two-dimensional CFT\, which gives the theory its name. The talk is
based on joint work with Scott Collier\, Beatrix Mühlmann and Victor Rod
riguez.\n\nTalk is online but we will meet in CP 303 to watch it.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Upamanyu Moitra (ICTP)
DTSTART:20231117T183000Z
DTEND:20231117T193000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/65
DESCRIPTION:Title: Entanglement Entropy in String Compactifications\nby Upamanyu
Moitra (ICTP) as part of Theoretical Physics Seminars (Kentucky)\n\nLectu
re held in CP 303.\n\nAbstract\nThe finiteness of entanglement entropy in
string theory has crucial implications for the information paradox\, quant
um gravity\, and holography. In my talk\, I will describe the recent progr
ess made on establishing this finiteness. I will describe the orbifold con
struction appropriate for analyzing entanglement in string theory\, the ta
chyonic divergences that one encounters and how we get a finite and calcul
able answer for the entanglement entropy\, including ten-dimensional strin
g theory and compactification to lower dimensions. (Based on works in coll
aboration with Atish Dabholkar)\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Takuya Yoda (Kyoto U)
DTSTART:20231101T173000Z
DTEND:20231101T183000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/66
DESCRIPTION:Title: Toward chaos in string scatterings\nby Takuya Yoda (Kyoto U)
as part of Theoretical Physics Seminars (Kentucky)\n\nLecture held in CP 3
03.\n\nAbstract\nRecently\, black holes have come to be regarded as chaoti
c objects. We can expect that the origin of this black hole chaos is attri
buted to some string dynamics from the viewpoint of the black hole-string
correspondence. In this talk\, we present our series of studies aimed at i
dentifying the string dynamics which give rise to black hole chaos. The co
ntents are as follows:\n(1) Transient chaos analysis in string scatterings
at tree level\n(2) Strategies for computing higher genus corrections: non
-trivial saddles in string scattering amplitudes\n(3) String-like melon di
agrams exhibiting fractal behavior\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/66/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Debarghya Chakraborty (UK)
DTSTART:20231108T183000Z
DTEND:20231108T193000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/67
DESCRIPTION:Title: Temperature Dependence of Lanczos Coefficients\nby Debarghya
Chakraborty (UK) as part of Theoretical Physics Seminars (Kentucky)\n\nLec
ture held in CP 303.\n\nAbstract\nThere has been a resurgence of interest
in the Lanczos method as an efficient way of describing operator dynamics.
The starting point is the thermal autocorrelation function that endows th
e Lanczos coefficients with temperature dependence. I will describe how t
he temperature dependence of the Lanczos coefficients can be recast as a c
lassical integrable system which can be formally solved as an initial valu
e problem. I will give examples and discuss potential applications.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Partha Mukhopadhyay (IMSc (Chennai))
DTSTART:20231213T183000Z
DTEND:20231213T193000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/68
DESCRIPTION:Title: Construction of Poincaré invariant theories on a lattice\nby
Partha Mukhopadhyay (IMSc (Chennai)) as part of Theoretical Physics Semin
ars (Kentucky)\n\nLecture held in CP 303.\n\nAbstract\nIn constructing lat
tice versions of physical theories\, usually the spacetime symmetries are
given up. This is because of the use of difference approximation of the de
rivative operator which does not satisfy Leibniz rule. The same is respons
ible for the fermion doubling problem and the associated loss of chirality
. We introduce a non-local lattice derivative\, hereafter to be called log
arithmic discrete derivative (LDD)\, as it admits a logarithmic expansion
in powers of the difference operator and a formal lattice integral (LI) wh
ich is inverse of LDD. The pair (LDD\, LI) can be shown to satisfy the sam
e differential and integral calculi of the continuum. We demonstrate how t
he pair can be used to construct lattice theories with Poincaré invarianc
e. A striking property of the resulting model is a local correspondence wh
ich says that local equations of the continuum theory still hold true on t
he lattice\, site-wise. Although such a construction looks very formal in
position space\, in momentum space the action takes a simple form which ma
y allow for numerical simulations. We show that the same momentum space re
sults can also be obtained by using summation\, instead of LI\, by using a
technique involving finer lattices. Similar concept was earlier arrived a
t by G. Bergner while studying SLAC-type non-local derivatives. We explain
how LDD is related to SLAC derivative and indicate how the new understand
ing of locality in position space could potentially allow for more effecti
ve use of non-local derivatives in lattice studies. Time permitting\, we s
hall also discus a generalisation of the construction to a class of curved
backgrounds and another form of the lattice derivative that achieves the
same thing but takes the form of an inverse sine hyperbolic function.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sandip Trivedi (TIFR - Mumbai)
DTSTART:20240214T190000Z
DTEND:20240214T200000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/69
DESCRIPTION:Title: Jackiw-Teitleboim Gravity in deSitter Space\nby Sandip Trived
i (TIFR - Mumbai) as part of Theoretical Physics Seminars (Kentucky)\n\nLe
cture held in CP 303.\n\nAbstract\nWe canonically quantise Jackiw-Teitlebo
im gravity in de Sitter space\, with particular attention to the problem
of time. Our results suggest an holographic interpretation for global de
Sitter space\, in this two dimensional setting.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/69/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zohar Komargodski (SUNY Stony Brook)
DTSTART:20240301T200000Z
DTEND:20240301T210000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/70
DESCRIPTION:Title: Defects in magnets and gauge theories\nby Zohar Komargodski (
SUNY Stony Brook) as part of Theoretical Physics Seminars (Kentucky)\n\nLe
cture held in CP 179.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/70/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diptarka Das (IIT Kanpur)
DTSTART:20240325T180000Z
DTEND:20240325T190000Z
DTSTAMP:20260404T095031Z
UID:UKYhepth/71
DESCRIPTION:Title: Chaotic and Thermal Aspects in the String S-Matrix\nby Diptar
ka Das (IIT Kanpur) as part of Theoretical Physics Seminars (Kentucky)\n\n
Lecture held in CP 179.\n\nAbstract\nWe compute tree level scattering ampl
itudes involving more than one highly excited states in bosonic string the
ory. We use these amplitudes to understand chaotic and thermal aspects of
the excited string states lending support to the Susskind-Horowitz- Polchi
nski correspondence principle. The unaveraged amplitudes exhibit chaos in
the resonance distribution as a function of kinematic parameters\, which c
an be described by random matrix theory. Upon coarse-graining these amplit
udes exponentiate\, and give certain thermal indications.\n
LOCATION:https://stable.researchseminars.org/talk/UKYhepth/71/
END:VEVENT
END:VCALENDAR