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BEGIN:VEVENT
SUMMARY:Henry Lin (Princeton University)
DTSTART:20200429T160000Z
DTEND:20200429T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/1
DESCRIPTION:Title: Bootstrapping Random Matrix Models\nby Henry Lin
(Princeton University) as part of Simons Bootstrap Collaboration Seminar S
eries\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Damon Binder (Princeton University)
DTSTART:20200506T140000Z
DTEND:20200506T150000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/2
DESCRIPTION:Title: Deligne categories in QFT\nby Damon Binder (Princ
eton University) as part of Simons Bootstrap Collaboration Seminar Series\
n\n\nAbstract\nIn QFT\, we often analytically continue the number of field
s\, or the number of spatial dimensions\, from the integers to real number
s. Despite its usefulness\, the exact mathematical meaning of this procedu
re is obscure. In recent work with Slava Rychkov\, arXiv:1911.07895\, we s
how that the appropriate language is provided by symmetric tensor categori
es\, with specific constructions by Pierre Deligne describing O(n)\, U(n)
and S_n symmetries for any real value of n. This language allows us to des
cribe theories with both integer and non-integer numbers of fields in a un
ified framework\, shedding light on previously puzzling aspects of analyti
cally continued theories.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Baurzhan Mukhametzhanov (IAS)
DTSTART:20200513T160000Z
DTEND:20200513T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/3
DESCRIPTION:Title: Beurling-Selberg extremization and modular bootstrap
at high energies\nby Baurzhan Mukhametzhanov (IAS) as part of Simons B
ootstrap Collaboration Seminar Series\n\n\nAbstract\nWe consider modular i
nvariance of 2d CFTs. Combining the high-temperature limit of the partitio
n function with ideas of tauberian theory we derive upper/lower bounds on
the number of operators in a given window of scaling dimensions at high en
ergies. This gives precise meaning to Cardy formula. The bounds depend on
a choice of functions that majorize/minorize the characteristic function o
f an interval and have Fourier of finite support. Optimization of the boun
ds over this choice turns out to be the Beurling-Selberg problem. We revie
w solution of this optimization problem and present corresponding bounds.
For intervals of integer size the bounds are saturated by known modular in
variant partition functions.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Abhijit Gadde (TIFR)
DTSTART:20200527T160000Z
DTEND:20200527T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/4
DESCRIPTION:Title: Modularity of supersymmetric partition functions\
nby Abhijit Gadde (TIFR) as part of Simons Bootstrap Collaboration Seminar
Series\n\n\nAbstract\nIn this talk\, I will present a novel modular prope
rty of 4d N=1 supersymmetric partition functions of supersymmetric theorie
s with R-symmetry. It is a generalization of the modular invariance of the
\nsupersymmetric partition function of two-dimensional supersymmetric theo
ries on a torus i.e. of the elliptic genus. It comes from requiring consis
tency of partition functions under gluing and\, among\nother things\, can
be used to rederive the supersymmetric Cardy formula for four-dimensional
gauge theories that has played a key role in computing the entropy of supe
rsymmetric black holes.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yin-Chen He (Perimeter Institute)
DTSTART:20200603T160000Z
DTEND:20200603T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/5
DESCRIPTION:Title: O(N) Non-Wilson-Fisher Kinks: Deconfined Phase Transi
tion and Beyond\nby Yin-Chen He (Perimeter Institute) as part of Simon
s Bootstrap Collaboration Seminar Series\n\n\nAbstract\nIn this talk I wil
l discuss a family of kinks of the O(N) numerical bootstrap bounds\, which
are sharply different from the well-known kinks of O(N) Wilson-Fisher CFT
s. The nature of these new kinks remains mysterious\, but we managed to un
derstand few special cases\, hinting interesting physics. In 2D\, the O(4)
non-Wilson-Fisher kink turns out to be the familiar SU(2)_1 Wess-Zumino-W
itten model. We further consider its dimensional continuation towards the
3D SO(5) deconfined phase transition\, and we find the kink disappears at
fractional dimension (around D=2.7)\, suggesting the 3D SO(5) deconfined p
hase transition is pseudo-critical (also called complex CFT). I will also
talk about the infinite-N limit\, where we have obtained the analytical fo
ur point correlation function for arbitrary space-time dimensions. The inf
inite-N solution contains a full tower of higher spin conserved current\,
opening the possibility of a new family of CFTs for finite N.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tom Hartman (Cornell)
DTSTART:20200617T160000Z
DTEND:20200617T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/6
DESCRIPTION:Title: Applications of the modular bootstrap\nby Tom Har
tman (Cornell) as part of Simons Bootstrap Collaboration Seminar Series\n\
n\nAbstract\nI will describe recent progress on the connections among the
modular bootstrap\, the sphere packing problem\, and quantum gravity in th
ree dimensions. This leads us toward a holographic duality between Narain
CFTs averaged over moduli and a Chern-Simons-like theory of "U(1) gravity.
"\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sasha Zhiboedov (CERN)
DTSTART:20200624T160000Z
DTEND:20200624T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/7
DESCRIPTION:Title: An Analytic Toolkit for the S-matrix Bootstrap\nb
y Sasha Zhiboedov (CERN) as part of Simons Bootstrap Collaboration Seminar
Series\n\n\nAbstract\nWe revisit analytical methods for constraining the
nonperturbative S-matrix of unitary\, relativistic\, gapped theories in d
≥3 spacetime dimensions. We assume extended analyticity of the two-to-tw
o scattering amplitude and use it together with elastic unitarity to devel
op two natural expansions of the amplitude. One is the threshold (non-rela
tivistic) expansion and the other is the large spin expansion. The two are
related by the Froissart-Gribov inversion formula. When combined with cro
ssing and a local bound on the discontinuity of the amplitude\, this allow
s us to constrain scattering at finite energy and spin in terms of the low
-energy parameters measured in the experiment. Finally\, we discuss the mo
dern numerical approach to the S-matrix bootstrap and how it can be improv
ed based on the results of our analysis.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NO SEMINAR
DTSTART:20200701T160000Z
DTEND:20200701T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/8
DESCRIPTION:by NO SEMINAR as part of Simons Bootstrap Collaboration Semina
r Series\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Parijat Dey (Uppsala University)
DTSTART:20200708T160000Z
DTEND:20200708T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/9
DESCRIPTION:Title: Operator expansions and layer susceptibility in BCFT<
/a>\nby Parijat Dey (Uppsala University) as part of Simons Bootstrap Colla
boration Seminar Series\n\n\nAbstract\nWe show that in boundary CFTs (BCFT
s)\, there exists a one-to-one correspondence between the boundary operato
r expansion of the two point correlation function and a power series expan
sion of the layer susceptibility. This allows the direct identification of
the boundary spectrum and expansion coefficients from the layer susceptib
ility which is easier to compute. To show how it works we compute the two
point function < phi_i phi^i > of the O(N) model at the extraordinary tran
sition in 4-\\epsilon dimensions to order \\epsilon. Via the bulk operator
product expansion\, this fixes a part of the spectrum of the bulk CFT to
order \\epsilon^2.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Xinan Zhou (Princeton University)
DTSTART:20200715T160000Z
DTEND:20200715T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/10
DESCRIPTION:Title: All holographic four-point correlators in maximally
supersymmetric CFTs\nby Xinan Zhou (Princeton University) as part of S
imons Bootstrap Collaboration Seminar Series\n\n\nAbstract\nIn this talk\,
I will introduce a powerful new method to constructively derive all tree-
level four-point functions in holographic CFTs with maximal supersymmetry.
I will introduce the notion of maximally R-symmetry violating (MRV) limit
\, which is key to our construction. In this limit\, the correlators simpl
ify drastically and become easy to compute. I will then show that the full
correlators can be reconstructed from the MRV limit by using symmetries.
A remarkable feature is that the four-point functions do not have intrinsi
c contact interactions\, and can be expressed as sums of exchanges alone.
Using this method we reproduce the known results for AdS5xS5 dual to 4d N=
4 SYM\, and also compute all four-point functions from AdS4xS7 and AdS7xS4
\, dual respectively to 3d N=8 ABJM and the 6d (2\,0) theory. Along the wa
y\, I will review the relation with the previous developments including th
e bootstrap methods\, and point out various intriguing similarities with t
he flat space scattering amplitudes. I will also make brief comments on va
rious future extensions of this program.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/10
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Henry Maxfield (UCSB)
DTSTART:20200722T160000Z
DTEND:20200722T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/11
DESCRIPTION:Title: 3D gravity near extremality and JT gravity with defe
cts\nby Henry Maxfield (UCSB) as part of Simons Bootstrap Collaboratio
n Seminar Series\n\n\nAbstract\nA potential inconsistency of 3D pure gravi
ty was recently observed in the form of a negative density of states for n
ear-extremal black holes. I will argue that this pathology is cured by inc
luding additional topologies in the path integral\, for which no classical
solution exists. Along the way\, I introduce a closely-related two-dimens
ional theory generalising JT gravity by including dynamical defects\, whic
h is dual to a matrix integral. Finally\, I will discuss the problem from
the perspective of the modular bootstrap.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/11
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kurt Hinterbichler (Case Western)
DTSTART:20200729T160000Z
DTEND:20200729T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/12
DESCRIPTION:Title: Unitarization in Kaluza Klein theory and a bootstrap
for geometry\nby Kurt Hinterbichler (Case Western) as part of Simons
Bootstrap Collaboration Seminar Series\n\n\nAbstract\nThe infinite towers
of massive particles present in Kaluza Klein reductions of Einstein gravit
y conspire to soften the high-energy behavior of the scattering of massive
spin-2 states. The mechanism by which this occurs leads to a bootstrap p
rocedure\, analogous to the conformal bootstrap\, that yields new non-triv
ial constraints on the eigenvalue spectra of closed Einstein manifolds.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/12
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Meltzer (Caltech)
DTSTART:20200805T160000Z
DTEND:20200805T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/13
DESCRIPTION:Title: The Inversion Formula and the Spectrum of the O(2) M
odel\nby David Meltzer (Caltech) as part of Simons Bootstrap Collabora
tion Seminar Series\n\n\nAbstract\nThe Lorentzian inversion formula proves
that CFT data is analytic in spin and that operators can be organized on
Regge trajectories. In this talk we investigate the leading Regge trajecto
ries of the O(2) model using a combination of numerical and analytical tec
hniques. We show that the predictions of the inversion formula for spinnin
g operators agrees with the numerical predictions. Furthermore\, we give m
ore evidence that scalar operators lie on Regge trajectories and also comp
ute the Regge intercept of the O(2) model. Using this data\, we are able t
o make predictions for the four-point function of the fundamental\, charge
1 scalar in both Euclidean and Lorentzian regimes.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/13
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lorenz Eberhardt (IAS)
DTSTART:20200819T160000Z
DTEND:20200819T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/14
DESCRIPTION:Title: Scattering equations in AdS\nby Lorenz Eberhardt
(IAS) as part of Simons Bootstrap Collaboration Seminar Series\n\n\nAbstr
act\nI will discuss an analogue of the CHY formalism in AdS. Considering t
he biadjoint scalar theory on AdS\, I will explain how to rewrite all the
tree-level amplitudes as an integral over the moduli space of punctured Ri
emann spheres. Contrary to the flat space\, the scattering equations are o
perator-valued. The resulting formula is motivated via a bosonic ambitwist
or string on AdS and can be proven to be equivalent to the corresponding W
itten diagram computation by applying a series of contour deformations. (N
OTE NEW ZOOM LINK)\n\nhttps://cornell.zoom.us/j/92760097069?pwd=YmdpOVMweG
p1RklkTk5wNFhlRFN6UT09\n\nNOTE NEW ZOOM LINK\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/14
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zahra Zahraee (McGill)
DTSTART:20200902T160000Z
DTEND:20200902T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/15
DESCRIPTION:Title: The leading trajectory in the 2+1D Ising CFT\nby
Zahra Zahraee (McGill) as part of Simons Bootstrap Collaboration Seminar
Series\n\n\nAbstract\nIn this talk we will discuss the low-spin analyticit
y of the leading Regge trajectories in 3D Ising CFT. The analysis is perfo
rmed by using the Lorentzian inversion formula and the precise spectrum (o
btained from the numerical conformal bootstrap) as an input. Specifically\
, we will answer two questions\; first\, can the leading Regge trajectorie
s be extended to J<2 and include spin 0 operators? We will provide evidenc
e that the answer to this question is affirmative. Second\, what is the va
lue of the intercept for the leading Regge trajectory? We will argue that
the intercept of the model is below unity: j∗ ≈ 0.8\, indicating regul
arity of the spectrum. Lastly\, we will indicate how our observation is su
pported by analytics in the large-N O(N) model.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/15
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Slava Rychkov (IHES and ENS)
DTSTART:20200909T160000Z
DTEND:20200909T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/16
DESCRIPTION:Title: Musings and some results about non-perturbative RG\nby Slava Rychkov (IHES and ENS) as part of Simons Bootstrap Collaborat
ion Seminar Series\n\n\nAbstract\nI will motivate why non-perturbative RG
is an unfinished business\, and what kind of developments are needed in th
is area. I will then describe recent rigorous work about RG fixed points i
n a model of symplectic fermions with a long-range kinetic term and a loca
l quartic interaction. This may be the simplest field theory in which a no
n-gaussian fixed point can be shown to exist without any truncation or app
roximation. It is a perfect toy model where various folklore properties of
RG fixed points (universality of critical exponents\, conformal invarianc
e\, etc) could be examined explicitly. It also offers some hints for bette
r numerical implementations of non-perturbative RG. Based on 2008.04361 wi
th Alessandro Giuliani and Vieri Mastropietro.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/16
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Balt van Rees (Ecole Polytechnique)
DTSTART:20200923T160000Z
DTEND:20200923T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/17
DESCRIPTION:Title: Bootstrapping defects and boundaries for the free sc
alar field\nby Balt van Rees (Ecole Polytechnique) as part of Simons B
ootstrap Collaboration Seminar Series\n\n\nAbstract\nIs there any room for
non-trivial unitary and conformal defects in the theory of a single free
massless scalar field? And what about boundaries? We use the free scalar e
quation of motion and the structure of the bulk-to-defect operator expansi
on to rule out the existence of such defects in several (co-)dimensions. F
or boundaries we are led to a non-trivial system of crossing equations tha
t we analyze numerically in four bulk dimensions. We show that large regio
ns of parameter spaces are excluded\, but a 'kink' in the numerical bounds
obeys all our consistency checks and might be an indication of a new conf
ormal boundary condition.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/17
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dalimil Mazac (IAS)
DTSTART:20200930T160000Z
DTEND:20200930T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/18
DESCRIPTION:Title: Dispersive CFT sum rules\nby Dalimil Mazac (IAS)
as part of Simons Bootstrap Collaboration Seminar Series\n\n\nAbstract\nI
will motivate and discuss the notion of dispersive sum rules in conformal
field theory. The defining property of these sum rules is that they suppr
ess double-twist operators. This makes them very useful for various analyt
ic bootstrap applications. Physically\, they arise from consistency in the
Lorentzian signature. Dispersive sum rules can be derived through several
equivalent approaches: 1) as analytic functionals applied to the crossing
equation\, 2) by expanding the conformal dispersion relation\, 3) as the
Polyakov condition in Mellin space and 4) as superconvergence sum rules. I
will discuss how these approaches are unified through the Polyakov-Regge
expansion of the correlator. I will mention some applications\, including
an extremal functional for spin-2 gap maximization. Based on https://arxiv
.org/pdf/2008.04931.pdf.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/18
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Guerrieri (Tel Aviv University)
DTSTART:20201007T160000Z
DTEND:20201007T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/19
DESCRIPTION:Title: Exploring the Dual S-matrix Bootstrap\nby Andrea
Guerrieri (Tel Aviv University) as part of Simons Bootstrap Collaboration
Seminar Series\n\n\nAbstract\nObtaining numerical rigorous bounds on QFT
observables using the S-matrix Bootstrap is often a difficult task. In thi
s talk I will discuss how duality in optimization theory provides an alter
native and efficient formulation of the problem. In particular\, I will f
ocus on 2D gapped systems with stable particles of different masses and bo
und states. I will explain how their rich analytic and crossing structure
is inherited by the dual variables and how the unitarity constraints are a
utomatically saturated. This will serve as a toy model to bootstrap some p
opular physical systems.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/19
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Max Metliski (MIT)
DTSTART:20201014T160000Z
DTEND:20201014T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/20
DESCRIPTION:Title: Boundary criticality of the O(N) model in d = 3 crit
ically revisited.\nby Max Metliski (MIT) as part of Simons Bootstrap C
ollaboration Seminar Series\n\n\nAbstract\nIt is known that the classical
O(N) model in dimension d > 3 at its bulk critical point admits three boun
dary universality classes: the ordinary\, the extra-ordinary and the speci
al. The extraordinary fixed point corresponds to the bulk transition occur
ring in the presence of an ordered boundary\, while the special fixed poin
t corresponds to a boundary phase transition between the ordinary and the
extra-ordinary classes. While the ordinary fixed point survives in d = 3\,
it is less clear what happens to the extra-ordinary and special fixed poi
nts when d = 3 and N is greater or equal to 2. I'll show that formally tre
ating N as a continuous parameter\, there exists a critical value Nc > 2 s
eparating two distinct regimes. For N < Nc the extra-ordinary fixed point
survives in d = 3\, albeit in a modified form: the long-range boundary ord
er is lost\, instead\, the order parameter correlation function decays as
a power of log r. For N > Nc there is no fixed point with order parameter
correlations decaying slower than power law. I'll discuss several scenario
s for the evolution of the system with N through Nc. One of these scenario
s might explain recent numerical results on boundary criticality in 2+1D q
uantum spin systems with SO(3) symmetry.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/20
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ami Katz (Boston University)
DTSTART:20201104T170000Z
DTEND:20201104T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/21
DESCRIPTION:Title: Nonperturbative dynamics in (2+1)d from Hamiltonian
truncation\nby Ami Katz (Boston University) as part of Simons Bootstra
p Collaboration Seminar Series\n\n\nAbstract\nWe use Lightcone Conformal T
runcation to study phi^4 theory in (2+1)d.\nThis theory contains divergenc
es. In Hamiltonian truncation methods these cannot be dealt with via a si
mple local counter-term\, requiring a different approach.\nWe implement a
state-dependent renormalization procedure\, which we find to be \nessentia
l to having the mass gap close at a scheme dependent critical coupling.\nW
e then calculate real time correlation functions of local operators\nboth
at generic strong coupling and near the critical point . Near the critica
l point \nwe find evidence for IR universality and the vanishing of the tr
ace of the stress tensor.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/21
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marco Serone (SISSA)
DTSTART:20201111T170000Z
DTEND:20201111T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/22
DESCRIPTION:Title: elf-Dualities and Renormalization Dependence of the
Phase Diagram in 3d O(N) Vector Models\nby Marco Serone (SISSA) as par
t of Simons Bootstrap Collaboration Seminar Series\n\n\nAbstract\nIn the c
lassically unbroken phase\, 3d $O(N)$ symmetric $\\phi^4$ vector models ad
mit two equivalent descriptions connected by a strong-weak duality closely
related to the one found by Chang and Magruder long ago. We determine the
exact analytic renormalization dependence of the critical couplings in th
e weak and strong branches as a function of the renormalization scheme (pa
rametrized by $\\kappa$) and for any $N$. It is shown that for $\\kappa=\\
kappa_*$ the two fixed points merge and then\, for $\\kappa<\\kappa_*$\, t
hey move into the complex plane in complex conjugate pairs\, making the ph
ase transition no longer visible from the classically unbroken phase. We v
erify these considerations by computing the perturbative series of the 3d
$O(N)$ models for the vacuum energy and for the mass gap up to order eight
\, and Borel resumming the series. In particular\, we provide numerical ev
idence for the self-duality and verify that in renormalization schemes whe
re the critical couplings are complex the theory is gapped.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/22
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aditya Hebbar (EPFL)
DTSTART:20201202T170000Z
DTEND:20201202T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/23
DESCRIPTION:Title: Spinning S-matrix Bootstrap in 4d\nby Aditya Heb
bar (EPFL) as part of Simons Bootstrap Collaboration Seminar Series\n\n\nA
bstract\nWe review unitarity and crossing constraints on scattering amplit
udes for particles with spin in four dimensional quantum field theories. A
s an application we study two to two scattering of neutral spin 1/2 fermio
ns in detail. Assuming Mandelstam analyticity of its scattering amplitude\
, we use the numerical S-matrix bootstrap method to estimate various non-p
erturbative bounds on quartic and cubic (Yukawa) couplings.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/23
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sourav Sarkar (Porto University)
DTSTART:20201209T170000Z
DTEND:20201209T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/24
DESCRIPTION:Title: A perturbative optical theorem for CFT and conformal
Regge theory.\nby Sourav Sarkar (Porto University) as part of Simons
Bootstrap Collaboration Seminar Series\n\n\nAbstract\nWe shall discuss a n
ew perturbative optical theorem for CFTs which computes the double discont
inuity of conformal correlators from the single discontinuities of lower o
rder correlators. We shall then use it to study the Regge limit of a four
point correlator at one loop and finite t'Hooft coupling. This incorporate
s contributions from tidal excitations that are packaged into am AdS verte
x function. We shall then discuss the flat space limit of these results an
d constrain the AdS vertex function for type IIB strings in AdS using the
corresponding flat space vertex function that is known.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/24
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alessandro Vichi (Universita' di Pisa)
DTSTART:20210120T170000Z
DTEND:20210120T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/25
DESCRIPTION:Title: The Good\, the Bad and the Unstable: a bootstrap stu
dy of O(3) and related models\nby Alessandro Vichi (Universita' di Pis
a) as part of Simons Bootstrap Collaboration Seminar Series\n\n\nAbstract\
nI will present the results of a numerical bootstrap study of the critical
O(3) vector model.\nUsing a two recently developed new algorithms\, it is
possible to put an upper bound on the dimension of the leading rank-4 sym
metric tensor. This operators is found to be relevant\, thus providing a n
umerical proof that systems described by the critical O(3) model\, such a
s classical Heisenberg ferromagnets at the Curie transition\, are unstable
to cubic anisotropy. I will briefly discuss the steps leading to this det
ermination and analyze the physical consequences. Based on arXiv:2011.1464
7\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/25
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Piotr Tourkine (LPTHE\, Sorbonne)
DTSTART:20210127T170000Z
DTEND:20210127T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/26
DESCRIPTION:Title: Scattering from production in 2d\nby Piotr Tourk
ine (LPTHE\, Sorbonne) as part of Simons Bootstrap Collaboration Seminar S
eries\n\n\nAbstract\nn this seminar\, I will talk about recent results abo
ut a numerical method to find unitary S-matrices. The method\, based on wo
rks of Atkinson\, was invented in the late 60s and was used as a proof of
existence of functions that satisfy all of the S-matrix axioms in 4d. Howe
ver\, it was not put in practical use.\nOur recent results concern the imp
lementation of those methods for S-matrices in two dimensions\, using two
different iterative schemes: a fixed-point iteration and Newton’s method
. Those schemes iterate the unitarity and dispersion relations\, and conve
rge to solutions to the S-matrix axioms. This numerical strategy provides
a solution to the problem of reconstructing the scattering amplitude start
ing from a given particle production probability. After a general introdu
ction\, the talk will be focused on how we implemented the algorithms\, wh
at they converge to\, and the conditions under which they converge. We wil
l see that the question of convergence naturally connects to the recent st
udy of the coupling maximization in the two-dimensional S-matrix bootstrap
. If time allows\, I’ll also comment on a fractal structure which we obs
erved to be related to the so-called CDD-ambiguities. I’ll conclude with
possible future directions. [In collaboration with Alexander Zhiboedov\,
based on http://arxiv.org/abs/2101.05211]\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/26
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ashley Milsted (Caltech)
DTSTART:20210203T170000Z
DTEND:20210203T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/27
DESCRIPTION:Title: Collisions of false-vacuum bubble walls in a quantum
spin chain\nby Ashley Milsted (Caltech) as part of Simons Bootstrap C
ollaboration Seminar Series\n\n\nAbstract\nWe study the real-time dynamics
of a small bubble of “false vacuum’’ in a quantum spin chain near c
riticality\, where the low-energy physics is described by a relativistic (
1+1)-dimensional quantum field theory. Such a bubble can be thought of as
a confined kink-antikink pair (a meson). We carefully construct bubbles so
that particle production does not occur until the walls collide. To achie
ve this in the presence of strong correlations\, we extend a Matrix Produc
t State (MPS) ansatz for quasiparticle wavepackets [Van Damme et al.\, arX
iv:1907.02474 (2019)] to the case of confined\, topological quasiparticles
. By choosing the wavepacket width and the bubble size appropriately\, we
avoid strong lattice effects and observe relativistic kink-antikink collis
ions. We use the MPS quasiparticle ansatz to identify scattering outcomes:
In the Ising model\, with transverse and longitudinal fields\, we do not
observe particle production despite nonintegrability (supporting recent nu
merical observations of nonthermalizing mesonic states). With additional i
nteractions\, we see production of confined and unconfined particle pairs.
Although we simulated these low-energy\, few-particle events with moderat
e resources\, we observe significant growth of entanglement with energy an
d with the number of collisions\, suggesting that increasing either will u
ltimately exhaust our methods. Quantum devices\, in contrast\, are not lim
ited by entanglement production\, and promise to allow us to go far beyond
classical methods. We anticipate that kink-antikink scattering in 1+1 dim
ensions will be an instructive benchmark problem for relatively near-term
quantum devices.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/27
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aninda Sinha (IIS)
DTSTART:20210210T170000Z
DTEND:20210210T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/28
DESCRIPTION:Title: Crossing symmetric dispersion relations in QFTs and
CFTs\nby Aninda Sinha (IIS) as part of Simons Bootstrap Collaboration
Seminar Series\n\n\nAbstract\nI will discuss crossing symmetric dispersion
relations in QFTs and CFTs. I will talk about connections with Polyakov
’s 1974 work\, the crossing symmetric Polyakov-Mellin bootstrap\, and co
nnections with fixed-t dispersion relations.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/28
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Adam Nahum (Oxford)
DTSTART:20210217T170000Z
DTEND:20210217T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/29
DESCRIPTION:Title: Self-dual criticality in the Z2 gauge-Higgs model in
three dimensions\nby Adam Nahum (Oxford) as part of Simons Bootstrap
Collaboration Seminar Series\n\n\nAbstract\nThe simplest topologically ord
ered phase in 2+1D is the deconfined phase of Z2 gauge theory. This phase
permits a duality that exchanges electric and magnetic excitations (“e
” and “m” particles). In the simplest lattice gauge theory formulati
on\, there is a self-dual line in the space of gauge and matter couplings.
Away from the self-dual line\, there are phase transitions out of the dec
onfined phase (the Higgs and confinement transitions) that are well unders
tood. But the phase transition onthe self dual line is still mysterious\,
and -- if continuous -- may be the simplest critical point for which we st
ill lack a useful continuum field theory description. After reviewing appl
ications of this model to quantum and classical statistical mechanics\, I
will describe Monte Carlo results for a wide range of observables at the s
elf-dual transition. The results indicate that it is a novel continuous tr
ansition. If time permits I will briefly mention a connection between ``ge
ometrical’’ (percolation) observables in the gauge-Higgs model and its
emergent one-form symmetries\, as well as some extensions of the model. W
ork with Andres Somoza and Pablo Serna (https://arxiv.org/abs/2012.15845).
\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/29
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simon Caron-Huot (McGill)
DTSTART:20210303T170000Z
DTEND:20210303T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/30
DESCRIPTION:Title: Sharp Boundaries for the Swampland\nby Simon Car
on-Huot (McGill) as part of Simons Bootstrap Collaboration Seminar Series\
n\n\nAbstract\nWe reconsider the problem of bounding higher derivative cou
plings in consistent weakly coupled gravitational theories\, starting from
general assumptions about analyticity and Regge growth of the S-matrix. H
igher derivative couplings are expected to be of order one in the units of
the UV cutoff. Our approach justifies this expectation and allows to prov
e precise bounds on the order one coefficients. Our main tool are dispersi
ve sum rules for the S-matrix. We overcome the difficulties presented by t
he graviton pole by measuring couplings at small impact parameter\, rather
than in the forward limit. We illustrate the method in theories containin
g a massless scalar coupled to gravity\, and in theories with maximal supe
rsymmetry.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/30
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yifei He (ENS)
DTSTART:20210407T160000Z
DTEND:20210407T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/31
DESCRIPTION:Title: S-matrix bootstrap in 3+1 dimensions: regularization
and dual problem\nby Yifei He (ENS) as part of Simons Bootstrap Colla
boration Seminar Series\n\n\nAbstract\nThe S-matrix bootstrap maps out the
space of S-matrices allowed by analyticity\, crossing and unitarity. For
2-to-2 scattering\, such space is an infinite dimensional convex space who
se boundary can be approached by maximizing a linear functional. I will de
scribe S-matrix bootstrap in 3+1 dimensions with focus on the equivalent d
ual problem which provides strict upper bounds for the regularized primal
problem. The dual problem has interesting practical and physical advantage
s over the primal problem\, and its variables are the dual partial waves w
ho are free from constraints yet directly related to the physical partial
waves. The formulation is done in the context of scalar fields related to
pion physics. This talk is based on joint work https://arxiv.org/abs/2103.
11484 with Martin Kruczenski.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/31
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sasha Zhiboedov (CERN)
DTSTART:20210414T160000Z
DTEND:20210414T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/32
DESCRIPTION:Title: Probing gravitational EFTs with the four-graviton am
plitude\nby Sasha Zhiboedov (CERN) as part of Simons Bootstrap Collabo
ration Seminar Series\n\n\nAbstract\nWe discuss constraints from perturbat
ive unitarity and crossing on the leading contributions of the higher-dime
nsion operators to the four-graviton amplitude in four spacetime dimension
s. We focus on the leading order effect due to exchange by massive degrees
of freedom which makes the amplitudes of interest IR finite. To test the
constraints we obtain nontrivial effective field theory data by computing
and taking the large mass expansion of the one-loop minimally-coupled four
-graviton amplitude with massive particles up to spin 2 circulating in the
loop. Remarkably\, the leading EFT corrections to Einstein gravity of phy
sical theories\, both string theory and QFT coupled to gravity\, end up in
islands which are much smaller than what is suggested by the generic boun
ds obtained from consistency of the 2-2 graviton scattering amplitude. We
discuss the underlying mechanism for this phenomenon.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/32
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Valentina Prilepina (Laval University\, Quebec\, and Lomonosov Uni
versity\, Moscow)
DTSTART:20210428T160000Z
DTEND:20210428T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/33
DESCRIPTION:Title: Recursion Relations for Five-Point Conformal Blocks:
A Practical Approach\nby Valentina Prilepina (Laval University\, Queb
ec\, and Lomonosov University\, Moscow) as part of Simons Bootstrap Collab
oration Seminar Series\n\n\nAbstract\nIn this talk\, I will consider five-
point functions in conformal field theories (CFTs) in d > 2 spacetime dime
nsions. I will put forward a concrete and practical ap- proach to computin
g global conformal blocks that appear in 5-point functions of arbitrary sc
alar operators in general CFTs. By exploiting the weight-shifting operator
formalism\, I will construct a simple set of recursion relations for gene
r- ating five-point blocks for arbitrary symmetric traceless exchange\, wh
ich may be utilized to reduce such blocks to linear combinations of scalar
exchange blocks with shifted external dimensions. Throughout\, I will res
trict attention to parity- even five-point functions in parity-preserving
CFTs. Our results may be seen as a natural generalization of the work of D
olan and Osborn to the 5-point case. Moving beyond the external scalar cas
e\, I will consider how to promote one of the external scalars to a spin-1
or a spin-2 operator. I will show a way to derive additional recursion re
lations which encode these blocks in terms of combinations of weight shift
ing operators acting on the seed blocks for external scalars. Lastly\, I w
ill discuss one possible application of these results. (Joint work with Da
vid Poland http://arxiv.org/abs/2103.12092).\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/33
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kamran Salehi Vaziri (EPFL)
DTSTART:20210505T160000Z
DTEND:20210505T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/34
DESCRIPTION:Title: Hamiltonian truncation in Anti-de Sitter spacetime\nby Kamran Salehi Vaziri (EPFL) as part of Simons Bootstrap Collaborati
on Seminar Series\n\n\nAbstract\nQuantum Field Theories in Anti-de Sitter
spacetime are often strongly coupled when the radius of AdS is large\, and
few methods are available to study them. In this work\, we develop a Hami
ltonian truncation method to compute the energy spectrum of QFTs in two-di
mensional AdS. The infinite volume of constant timeslices of AdS leads to
divergences in the energy levels. We propose a simple prescription to obta
in finite physical energies and test it with numerical diagonalization in
several models: the free massive scalar field\, φ4 theory\, Lee-Yang and
Ising field theory. Along the way\, we discuss spontaneous symmetry breaki
ng in AdS and derive a compact formula for perturbation theory in quantum
mechanics at arbitrary order. Our results suggest that all conformal bound
ary conditions for a given theory are connected via bulk renormalization g
roup flows in AdS\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/34
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Balt van Rees (Ecole Polytechnique)
DTSTART:20210512T160000Z
DTEND:20210512T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/35
DESCRIPTION:Title: Navigator Function for the Conformal Bootstrap\n
by Balt van Rees (Ecole Polytechnique) as part of Simons Bootstrap Collabo
ration Seminar Series\n\n\nAbstract\nCurrent numerical conformal bootstrap
techniques carve out islands in theory space by repeatedly checking wheth
er points are allowed or excluded. We propose a new method for searching t
heory space that replaces the binary information “allowed”/“excluded
” with a continuous “navigator” function that is negative in the all
owed region and positive in the excluded region. Such a navigator function
allows one to efficiently explore high-dimensional parameter spaces and s
moothly sail towards any islands they may contain. The specific functions
we introduce have several attractive features: they are everywhere well-de
fined\, can be computed with standard methods\, and evaluation of their gr
adient is immediate due to an SDP gradient formula that we provide. The la
tter property allows for the use of efficient quasi-Newton optimization me
thods\, which we illustrate by navigating towards the 3d Ising island.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/35
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sebastian Mizera (IAS)
DTSTART:20210519T160000Z
DTEND:20210519T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/36
DESCRIPTION:Title: Recent Progress on Crossing Symmetry\nby Sebasti
an Mizera (IAS) as part of Simons Bootstrap Collaboration Seminar Series\n
\n\nAbstract\nWe will review recent progress in revisiting the problem of
crossing symmetry in perturbative quantum field theories. The new approach
is based on analyzing saddle points of the worldline action\, using which
we show that analytic continuation between pairs of physical regions can
be obstructed only by a special class of anomalous thresholds. For planar
scattering processes with consecutive in/out states\, there is a concise e
xplanation for the absence of such singularities\, thus proving crossing s
ymmetry to all loops and multiplicities.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/36
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Junchen Rong (DESY)
DTSTART:20210915T160000Z
DTEND:20210915T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/37
DESCRIPTION:Title: The old conformal bootstrap revisited\nby Junche
n Rong (DESY) as part of Simons Bootstrap Collaboration Seminar Series\n\n
\nAbstract\nThe “old” conformal bootstrap was originally formulated by
Migdal and Polyakov (MP) as a method for calculating conformal dimensions
self-consistently. In this work we revisit the MP bootstrap and apply eff
icient multi-loop Feynman integral techniques in order to solve the corres
ponding equations. We obtain solutions at first order in the skeleton expa
nsion for finite coupling and for integer values of the spacetime dimensio
n. We focus in particular on the phi^3 theory in seven dimensions and the
O(N) vector models in three dimensions.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/37
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shota Komatsu\, CERN\, and Matthijs Hogervorst\, EPFL (CERN and EP
FL)
DTSTART:20210929T160000Z
DTEND:20210929T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/38
DESCRIPTION:Title: Cosmological correlators and bootstrap\nby Shota
Komatsu\, CERN\, and Matthijs Hogervorst\, EPFL (CERN and EPFL) as part o
f Simons Bootstrap Collaboration Seminar Series\n\n\nAbstract\nWe discuss
quantum field theory on a background de Sitter spacetime. In the first par
t (Shota)\, I will review basic notions on de Sitter\, such as the late-ti
me correlators\, the wave functions and dS/CFT\, with a particular emphasi
s on the difference between the correlators and the wave functions. I will
then explain the relation between de Sitter perturbation theory and AdS L
agrangian\, and briefly discuss analyticity. In the second part (Matthijs)
we analyze de Sitter correlators nonperturbatively\, like in the conventi
onal conformal bootstrap. In detail I will compare the notion of de Sitter
unitarity with its flat-space counterpart. Finally I will establish that
late-time correlators obey crossing equations that can be explored using b
ootstrap methods (as will be illustrated in a simple example).\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/38
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Avia Raviv Moshe (SCGP)
DTSTART:20211006T160000Z
DTEND:20211006T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/39
DESCRIPTION:Title: Renormalization group flows on line defects\nby
Avia Raviv Moshe (SCGP) as part of Simons Bootstrap Collaboration Seminar
Series\n\n\nAbstract\n(Based on https://arxiv.org/abs/2108.01117 with Gabr
iel Cuomo and Zohar Komargodski). In this talk\, we will consider line def
ects in d-dimensional CFTs. The ambient CFT places nontrivial constraints
on Renormalization Group (RG) flows on such line defects. We will see that
the flow on line defects is consequently irreversible and furthermore a c
anonical decreasing entropy function exists. This construction generalizes
the g theorem to line defects in arbitrary dimensions. We demonstrate thi
s generalization in a flow between Wilson loops in 4 dimensions.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/39
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vasilis Niarchos (University of Crete)
DTSTART:20211013T160000Z
DTEND:20211013T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/40
DESCRIPTION:Title: Conformal bootstrap with Reinforcement Learning\
nby Vasilis Niarchos (University of Crete) as part of Simons Bootstrap Col
laboration Seminar Series\n\n\nAbstract\nI will introduce a novel numerica
l treatment of the truncated conformal-bootstrap equations based on Reinfo
rcement Learning. I will discuss preliminary applications of a soft Actor-
Critic algorithm to two-dimensional CFTs\, where the Reinforcement-Learnin
g agent was asked to identify well-known theories like the 2D Ising and tr
i-critical Ising models\, or to track CFT data on the conformal manifold o
f the compactified scalar on a circle. The method can be used to study ar
bitrary (unitary or non-unitary) CFTs in any spacetime dimension. I will d
iscuss the advantages and disadvantages of the approach and the prospects
for future applications.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/40
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vladimir Kazakov (ENS)
DTSTART:20211020T160000Z
DTEND:20211020T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/41
DESCRIPTION:Title: Matrix Bootstrap Revisited\nby Vladimir Kazakov
(ENS) as part of Simons Bootstrap Collaboration Seminar Series\n\n\nAbstra
ct\nMatrix bootstrap is a new method for the numerical study of (multi)-ma
trix models in the planar limit\, using loop equations for moments of dist
ribution (Ward identities and factorization of traces at infinite N). The
lack of information associated with the use of only a finite number of lo
wer moments is supplemented by the conditions of positivity of the corre
lation matrix. The numerical solution of loop equations and these conditio
ns leads to inequalities for the lowest moments\, which rapidly converge t
o exact values with an increase in the number of used moments. In ou
r work https://arxiv.org/pdf/2108.04830.pdf\, the method was tested on the
example of the standard one-matrix model\, as well as on the case of an "
unsolvable" 2-matrix model with the interaction tr[A\, B]^2 and with quart
ic potentials. We propose a significant improvement of original H.Lin's pr
oposal for matrix bootstrap by introducing the relaxation procedure: we re
place the non-convex\, non-linear loop equations by convex inequalities.
The results look quite convincing and matrix bootstrap seems to be an in
teresting alternative to the Monte Carlo method. For example\, for \, the precision reaches 6 digits (with modest computer resources). I
will discuss the prospects for applying the method in other\, physically i
nteresting systems.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/41
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NO SEMINAR
DTSTART:20211110T170000Z
DTEND:20211110T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/42
DESCRIPTION:by NO SEMINAR as part of Simons Bootstrap Collaboration Semina
r Series\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/42
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sasha Zhiboedov (CERN)
DTSTART:20211117T170000Z
DTEND:20211117T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/43
DESCRIPTION:Title: Conformal Collider Telling Time\nby Sasha Zhiboe
dov (CERN) as part of Simons Bootstrap Collaboration Seminar Series\n\n\nA
bstract\nI will discuss the longitudinal structure of the state created by
a local operator in a conformal collider experiment. For this purpose\, I
will introduce a convenient class of light-ray operators sensitive to the
time-dependence of radiation and will discuss their properties. I will th
en examine the matrix elements of such light-ray operators (or generalized
event shapes). I will primarily focus on theories with a semi-classical g
ravity dual.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/43
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ying-Hsuan Lin (Harvard)
DTSTART:20211103T160000Z
DTEND:20211103T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/44
DESCRIPTION:Title: Numerical evidence for a Haagerup CFT\nby Ying-H
suan Lin (Harvard) as part of Simons Bootstrap Collaboration Seminar Serie
s\n\n\nAbstract\nWe numerically study an anyon chain based on the Haagerup
fusion category\, and find evidence that it leads in the long-distance li
mit to a conformal field theory whose central charge is ~2. Fusion categor
ies generalize the concept of finite group symmetries to non-invertible sy
mmetry operations\, and the Haagerup fusion category is the simplest one w
hich comes neither from finite groups nor affine Lie algebras. As such\, o
urs is the first example of conformal field theories which have truly exot
ic generalized symmetries.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/44
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NO SEMINAR
DTSTART:20211027T160000Z
DTEND:20211027T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/45
DESCRIPTION:by NO SEMINAR as part of Simons Bootstrap Collaboration Semina
r Series\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/45
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NO SEMINAR
DTSTART:20211124T170000Z
DTEND:20211124T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/46
DESCRIPTION:by NO SEMINAR as part of Simons Bootstrap Collaboration Semina
r Series\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/46
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nima Afkhami-Jeddi (University of Chicago)
DTSTART:20211201T170000Z
DTEND:20211201T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/47
DESCRIPTION:Title: Exploring CFTs via Bootstrap Deformations\nby Ni
ma Afkhami-Jeddi (University of Chicago) as part of Simons Bootstrap Colla
boration Seminar Series\n\n\nAbstract\nIn this talk\, I will explore the s
pace of solutions to the conformal crossing equations. By recasting the co
nformal bootstrap as a non-linear optimization problem\, I will describe a
n efficient method of converging to the solutions of these equations. Furt
hermore\, by deforming these solutions\, I will show that certain solution
s corresponding to known theories (e.g. Ising) are continuously connected
to those of other known theories in both correlator and modular bootstrap
contexts. Employing these techniques\, I will explore the space of non-uni
tary CFTs in 3d and provide evidence that the CFT data obtained in this wa
y is compatible with the ϵ-expansion for a non-unitary theory. Time permi
tting\, I will also discuss applications of these methods to the conformal
bootstrap islands.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/47
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Horacio Casini (Centro Atomico Bariloce)
DTSTART:20211215T170000Z
DTEND:20211215T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/48
DESCRIPTION:by Horacio Casini (Centro Atomico Bariloce) as part of Simons
Bootstrap Collaboration Seminar Series\n\n\nAbstract\nWe describe a propos
al for completeness in QFT. It asserts that the physical observable algebr
as produced by local degrees of freedom are the maximal ones compatible wi
th causality. We elaborate on equivalent statements to this idea such as t
he non-existence of generalized symmetries and the uniqueness of the net o
f algebras. For non-complete theories\, we explain how the existence of ge
neralized symmetries is unavoidable\, and further\, that they\nalways come
in dual pairs with precisely the same size"\, measured by an algebraic in
dex. Entropic order/disorder parameters can be defined that sense the dual
pairs of generalized symmetries and satisfy a "certainty relation". We br
iefly describe applications to understand the density of charged states an
d to holography.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/48
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shai Chester (Weizmann Institute)
DTSTART:20211208T170000Z
DTEND:20211208T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/49
DESCRIPTION:Title: Bootstrapping N=4 SYM on the Conformal Manifold\
nby Shai Chester (Weizmann Institute) as part of Simons Bootstrap Collabor
ation Seminar Series\n\n\nAbstract\nWe study the N = 4 SYM stress tensor m
ultiplet 4-point function for any value of the complexified coupling tau\,
and in principle any gauge group (we focus on SU(2) and SU(3) for simplic
ity). By combining non-perturbative constraints from the numerical bootstr
ap with two exact constraints from supersymmetric localization\, we are ab
le to compute upper bounds on low-lying CFT data (e.g. the Konishi) for an
y value of tau. These upper bounds are very close to the 4-loop weak coupl
ing predictions in the appropriate regime. We also give preliminary eviden
ce that these upper bounds become small islands under reasonable assumptio
ns\, in which case our method would provide a numerical solution to N = 4
SYM for any gauge group and tau.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/49
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brian Michael Mc Peak (Universita' di Pisa)
DTSTART:20220126T170000Z
DTEND:20220126T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/50
DESCRIPTION:Title: Error-Correcting Codes and Chiral CFTs at Higher Gen
us\nby Brian Michael Mc Peak (Universita' di Pisa) as part of Simons B
ootstrap Collaboration Seminar Series\n\n\nAbstract\nIt is known that ther
e is a relation between error-correcting codes\, lattices\, and chiral CFT
s. In this talk\, I will discuss how to apply this relation to CFTs on hig
her-genus Riemann surfaces. The modular transformations take a surprisingl
y simple form for these code CFTs\, so it is possible to enumerate all sol
utions to modular invariance for low values of the central charge. I will
show how the higher-genus constraints reduce the number of possible code C
FTs. I also hope to describe upcoming results concerning quantum error-cor
recting codes and (non-chiral) CFTs\, as well as the average over error-co
rrecting codes.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/50
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eric Perlmutter (Saclay)
DTSTART:20220209T170000Z
DTEND:20220209T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/51
DESCRIPTION:Title: Harnessing S-Duality in N=4 SYM & Supergravity as SL
(2\,Z)-Averaged Strings\nby Eric Perlmutter (Saclay) as part of Simons
Bootstrap Collaboration Seminar Series\n\n\nAbstract\nI will talk about t
his paper\, written with Scott Collier: https://arxiv.org/abs/2201.05093\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/51
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuan Xin (Yale)
DTSTART:20220216T170000Z
DTEND:20220216T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/52
DESCRIPTION:Title: Bootstrapping Conformal N_f = 4 QED3\nby Yuan Xi
n (Yale) as part of Simons Bootstrap Collaboration Seminar Series\n\n\nAbs
tract\nThree dimensional Quantum Electrodynamics coupled to four flavors o
f\nelectrons is a classic example of a strongly coupled gauged quantum\nfi
eld theory. While its low energy phase is believed to be conformal\nby man
y previous studies in various approaches\, the determination of\nits criti
cal parameters lacks a conclusive answer. We present the\nresults of a con
formal bootstrap study of this theory. We find that\nthe scaling dimension
s of the lowest-charge monopole operator and the\nadjoint fermion bilinear
operator can be bounded in a closed region\nafter implementing spectrum a
ssumptions inspired by the large-N_f\nperturbative predictions and a novel
interval positivity constraint on\nthe next-lowest-charge monopole operat
or. The bootstrap constraints on\nthe conserved current central charges ar
e comfortably consistent with\nlarge-N_f perturbation theory\, suggesting
that at least part of the\nlarge-N_f perturbative predictions form a consi
stent solution to\ncrossing. We will discuss the validity of the assumptio
ns we used and\ncompare against lattice simulations and previous bootstrap
study\nresults.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/52
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cyuan-Han Chang and Ian Moult (Caltech and Yale)
DTSTART:20220302T170000Z
DTEND:20220302T180000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/53
DESCRIPTION:Title: Conformal Colliders Meet the LHC\nby Cyuan-Han C
hang and Ian Moult (Caltech and Yale) as part of Simons Bootstrap Collabor
ation Seminar Series\n\n\nAbstract\nEnergy correlators are defined as matr
ix elements of products of average null energy (ANEC) operators. They are
important observables for collider physics and encode nontrivial Lorentzia
n dynamics of the theory. In this two part talk\, we will discuss both the
theoretical structure of multi-point energy correlators\, and their measu
rement in real world collider experiments.\n\nIn the first part of the tal
k (by Cyuan-Han Chang)\, we will show that Lorentz symmetry implies that e
nergy correlators can be decomposed into special functions called celestia
l blocks. As an example\, we will consider the three-point energy correlat
or in N=4 SYM at weak and strong coupling and compute their celestial bloc
k decomposition using inversion formulas. We will also discuss a crossing
equation satisfied by the three-point energy correlators and perform a lig
htcone bootstrap analysis to show that a certain type of double-twist oper
ator should exist in the spectrum.\n\nIn the second part of the talk (by I
an Moult)\, we show that the high energies of the Large Hadron Collider (L
HC)\, together with the exceptional resolution of its detectors\, allow mu
lti-point correlation functions of energy flow operators to be directly me
asured within jets for the first time. We will compare predictions from th
e light-ray OPE for the scaling properties and shape dependence of multi-p
oint correlators with LHC data\, and highlight how improved theoretical un
derstanding of these correlators can have a significant impact on our unde
rstanding of QCD at the LHC.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/53
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tom Hartman (Cornell)
DTSTART:20220413T160000Z
DTEND:20220413T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/54
DESCRIPTION:Title: Semiclassical 3D gravity as an average large-c CFT\nby Tom Hartman (Cornell) as part of Simons Bootstrap Collaboration Sem
inar Series\n\n\nAbstract\nGravity in AdS has Euclidean wormhole solutions
that are puzzling from the point of view of AdS/CFT because they do not s
atisfy factorization. In particular\, they do not satisfy some of the usua
l bootstrap axioms. I will describe how in 3D gravity\, these solutions ar
e reproduced by averaging over approximate solutions to the 2D bootstrap e
quations. This suggests that low-energy gravity should be understood as sa
tisfying the bootstrap axioms only in an averaged sense\, once black holes
are included in the bulk.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/54
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Karthik Prabhu (UCSB)
DTSTART:20220511T160000Z
DTEND:20220511T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/55
DESCRIPTION:Title: Infrared finite scattering in QFT & quantum gravity<
/a>\nby Karthik Prabhu (UCSB) as part of Simons Bootstrap Collaboration Se
minar Series\n\n\nAbstract\nThe “infrared problem” is the generic emis
sion of an infinite number of low-frequency quanta in any scattering proce
ss with massless fields. The “out” state contains an infinite number o
f such quanta which implies that it does not lie in the standard Fock repr
esentation. Consequently\, the standard S-matrix is undefined as a map bet
ween “in” and “out” states in the standard Fock space. This fact i
s due to the existence of a low-frequency tail of the radiation field i.e.
the memory effect. In massive QED\, the Faddeev-Kulish representations ha
ve been argued to yield an I.R. finite S-matrix. We clarify the “preferr
ed ” status of such representations as eigenstates of the conserved “l
arge gauge charge’' at spatial infinity. We prove a “No-Go” theorem
for the existence of a suitable Hilbert space analogously constructed in m
assless QED\, QCD\, linearized quantum gravity with massive/massless sourc
es\, and in full quantum gravity. We then suggest an “infrared-finite”
formulation of scattering theory in terms of correlation functions withou
t any a priori choice of “in/out” Hilbert spaces.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/55
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Philine van Vliet (DESY)
DTSTART:20221005T160000Z
DTEND:20221005T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/56
DESCRIPTION:Title: Bootstrapping line defects with O(2) symmetry\nb
y Philine van Vliet (DESY) as part of Simons Bootstrap Collaboration Semin
ar Series\n\n\nAbstract\nLine defects play an important role in our unders
tanding of QFTs\, explaining interesting phenomena in both condensed matte
r physics and high-energy theories\, and giving access to new data and obs
ervables.\nI will discuss recent work in which we explore 1d conformal lin
e defects with an additional O(2) symmetry using the numerical bootstrap.
The starting point is an agnostic approach\, where we perfom a systematic
bootstrap study of correlation functions between two canonical defect oper
ators: the displacement and the tilt. We then move on to study two specifi
c defects: a monodromy line defect and a localized magnetic field line def
ect. I will highlight the results of the latter one\, where we found a ser
ies of intriguing cusps which we investigate.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/56
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joan Elias MIró (ICTP)
DTSTART:20221019T160000Z
DTEND:20221019T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/57
DESCRIPTION:by Joan Elias MIró (ICTP) as part of Simons Bootstrap Collabo
ration Seminar Series\n\n\nAbstract\nIn this talk I will show how to isola
te Effective Field Theory scattering amplitudes in the space of non-pertur
bative two-to-two amplitudes\, using the S-matrix Bootstrap. I will introd
uce the Effective Field Theory cutoff in the S-matrix Bootstrap approach a
nd perform a detailed comparison of the full unitarity bounds with those o
btained using positivity and linearized unitarity.\nMoreover\, I will disc
uss the notion of Spin-Zero and UV dominance along the boundary of the all
owed amplitude space by introducing suitable observables. Finally\, I will
show that this construction also leads to novel bounds on operators of di
mension less than or equal to six.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/57
/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthew Walters (EPFL)
DTSTART:20221026T160000Z
DTEND:20221026T170000Z
DTSTAMP:20260404T110643Z
UID:SimonsBootstrapSeries/58
DESCRIPTION:Title: Towards a Nonperturbative Construction of the S-Matr
ix\nby Matthew Walters (EPFL) as part of Simons Bootstrap Collaboratio
n Seminar Series\n\n\nAbstract\nI will present a nonperturbative recipe fo
r directly computing the S-matrix in strongly-coupled QFTs. The method mak
es use of spectral data obtained in a Hamiltonian framework and can be app
lied to a wide range of theories\, including potentially QCD. After discus
sing the general approach\, I will demonstrate its application to the spec
ific example of the 2+1d O(N) model at large N\, using energy eigenstates
computed with Hamiltonian truncation to reproduce the full 2-to-2 scatteri
ng amplitude for arbitrary (complex) center-of-mass energy. I will also di
scuss many avenues for future applications and generalizations.\n
LOCATION:https://stable.researchseminars.org/talk/SimonsBootstrapSeries/58
/
END:VEVENT
END:VCALENDAR