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BEGIN:VEVENT
SUMMARY:Aswin Balasubramanian (Rutgers)
DTSTART;VALUE=DATE-TIME:20200512T190000Z
DTEND;VALUE=DATE-TIME:20200512T200000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/1
DESCRIPTION:Title: Fa
milies of Hitchin systems and N=2 theories\nby Aswin Balasubramanian (
Rutgers) as part of NHETC Seminar\n\n\nAbstract\nOver the last few years\,
the connection between 4d N=2 theories and Hitchin systems has led to a r
obust exchange of ideas between physics and mathematics. In my talk\, I wi
ll explain how to extend this dictionary to one between 4d N=2 physics and
the SL_N Hitchin system on a nodal UV Curve. I will then use this diction
ary to clarify certain questions concerning Coulomb branches of the corres
ponding Class S theories at various boundaries of the space of marginal pa
rameters. In mathematical terms\, I will describe tame SL_N Hitchin system
s as a flat family of integrable systems over \\bar{M}\, the Deligne-Mumfo
rd moduli space of the UV Curve. This is based on upcoming work with J. Di
stler and R. Donagi.\n
LOCATION:https://researchseminars.org/talk/nhetc/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ahsan Khan (Rutgers University)
DTSTART;VALUE=DATE-TIME:20201013T190000Z
DTEND;VALUE=DATE-TIME:20201013T200000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/2
DESCRIPTION:Title: Do
main Wall Junctions and Categorical Wall-Crossing\nby Ahsan Khan (Rutg
ers University) as part of NHETC Seminar\n\n\nAbstract\nThe wall-crossing
property of BPS states is an important feature common to centrally extende
d supersymmetric field theories. In this talk I will describe how the phys
ics of domain wall junctions combined with elementary ideas in homological
algebra leads to a categorical wall-crossing formula\; a universal descri
ption of how BPS Hilbert spaces jump across a wall of marginal stability.
\n\nBased on an upcoming paper with Greg Moore.\n
LOCATION:https://researchseminars.org/talk/nhetc/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ibrahima Bah (Johns Hopkins University)
DTSTART;VALUE=DATE-TIME:20201027T190000Z
DTEND;VALUE=DATE-TIME:20201027T200000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/3
DESCRIPTION:Title: An
omaly Inflow and topological mass terms\nby Ibrahima Bah (Johns Hopkin
s University) as part of NHETC Seminar\n\n\nAbstract\nIn this talk I will
discuss the role of topological mass terms in anomaly inflow. I will cons
ider QFTs obtained from brane setups in supergravity and discuss how the p
resence of bulk topological mass terms are responsible for several interes
ting features of the anomaly for the QFTs. In particular I will discuss h
ow these terms encode the anomalies for discrete symmetries.\n
LOCATION:https://researchseminars.org/talk/nhetc/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sergei Gukov (Caltech)
DTSTART;VALUE=DATE-TIME:20201103T200000Z
DTEND;VALUE=DATE-TIME:20201103T210000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/4
DESCRIPTION:Title: Co
bordism invariants from BPS q-series\nby Sergei Gukov (Caltech) as par
t of NHETC Seminar\n\n\nAbstract\nMany BPS partition functions depend on a
choice of additional structure: fluxes\, Spin or Spin^c structures\, etc.
In a context where the BPS generating series depends on a choice of Spin^
c structure we show how different limits with respect to the expansion var
iable q and different ways of summing over Spin^c structures produce diffe
rent invariants of homology cobordisms out of the BPS q-series. Based on a
recent work with Pavel Putrov and Sunghyuk Park.\n
LOCATION:https://researchseminars.org/talk/nhetc/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cristina Mondino (Perimeter Institute)
DTSTART;VALUE=DATE-TIME:20210223T180000Z
DTEND;VALUE=DATE-TIME:20210223T190000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/5
DESCRIPTION:Title: Pr
obing dark matter substructure with astrometric weak lensing\nby Crist
ina Mondino (Perimeter Institute) as part of NHETC Seminar\n\n\nAbstract\n
Low-mass structures of dark matter are expected to be entirely devoid of l
ight-emitting regions and baryons. Precisely because of this lack of baryo
nic feedback\, small-scale substructures of the Milky Way are a relatively
pristine testing ground for discovering aspects of dark matter microphysi
cs and primordial fluctuations on sub-galactic scales. I will present resu
lts from the first search for galactic dark matter subhalos with time-doma
in astrometric weak gravitational lensing. The analysis is based on a matc
hed-filter template of local lensing corrections to the proper motion of s
tars in the Magellanic Clouds and is most sensitive to compact dark struct
ures of ten million to a hundred million solar mass.\n
LOCATION:https://researchseminars.org/talk/nhetc/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicholas Rodd (UC Berkeley)
DTSTART;VALUE=DATE-TIME:20210309T180000Z
DTEND;VALUE=DATE-TIME:20210309T190000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/6
DESCRIPTION:Title: Tw
o new ideas for the axion dark matter program\nby Nicholas Rodd (UC Be
rkeley) as part of NHETC Seminar\n\n\nAbstract\nThe coming decade will bri
ng dramatic improvement in the axion dark matter program as new experiment
al designs move beyond the proof of principle stage. In this talk I will o
utline two new ideas that exploit this experimental progress. The first is
to combine the results from two or more instruments in order to perform i
nterferometry directly on the dark-matter wave. This technique reveals asp
ects of the axion signal that can be invisible to a single detector\, such
as the incident direction of the dark-matter wave. The second is to searc
h for relativistic axions in these experiments\, in particular future inst
ruments like dark-matter radio will be sensitive to axions produced in the
early universe that constitute a residual Cosmic axion Background (CaB).
Existing searches at\, for instance ADMX\, are not yet sensitive to a cosm
ic relic\, although if relativistic axions are produce in the late univers
e\, by for instance dark-matter decaying to axions\, then this is a signal
the experiments are already sensitive to\, but would miss with existing a
nalyses.\n
LOCATION:https://researchseminars.org/talk/nhetc/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Phiala Shanahan (MIT)
DTSTART;VALUE=DATE-TIME:20210323T170000Z
DTEND;VALUE=DATE-TIME:20210323T180000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/7
DESCRIPTION:Title: Ma
chine learning for physics: gauge-equivariant architectures\nby Phiala
Shanahan (MIT) as part of NHETC Seminar\n\n\nAbstract\nAs machine learnin
g algorithms continue to enable and accelerate physics calculations in nov
el ways\, the development of tailored physics-informed machine learning ap
proaches is becoming more sophisticated\, impactful\, and important. I wil
l give some broad context for this developing area\, with a focus on the c
hallenge of exact sampling from known probability distributions as relevan
t to lattice quantum field theory calculations in particle and nuclear phy
sics. I will discuss in particular flow-based generative models\, and desc
ribe how guarantees of exactness and the incorporation of complex symmetri
es (e.g.\, gauge symmetry) into model architectures can be achieved. I wil
l show the results of proof-of-principle studies that demonstrate that sam
pling from generative models can be orders of magnitude more efficient tha
n traditional Hamiltonian/hybrid Monte Carlo approaches in this context.\n
LOCATION:https://researchseminars.org/talk/nhetc/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ken Van Tilburg (NYU/Flatiron CCA)
DTSTART;VALUE=DATE-TIME:20210406T170000Z
DTEND;VALUE=DATE-TIME:20210406T180000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/8
DESCRIPTION:Title: St
ellar Basins of Gravitationally Bound Particles\nby Ken Van Tilburg (N
YU/Flatiron CCA) as part of NHETC Seminar\n\n\nAbstract\nI will describe a
nd explore the consequences of a peculiar physical phenomenon: volumetric
stellar emission into gravitationally bound orbits of weakly coupled parti
cles such as axions\, moduli\, hidden photons\, and neutrinos. While only
a tiny fraction of the instantaneous luminosity of a star (the vast majori
ty of the emission is into relativistic modes)\, the continual injection o
f these particles into a small part of phase space causes them to accumula
te over astrophysically long time scales\, forming what I call a "stellar
basin"\, in analogy with the geologic kind. The energy density of the Sola
r basin can surpass that of the relativistic Solar flux at Earth's locatio
n after only a million years\, for any sufficiently long-lived particle pr
oduced through an emission process whose matrix elements are unsuppressed
at low momentum. This observation has immediate and striking consequences
for direct detection experiments---including new limits on axion and hidde
n-photon parameter space independent of dark matter assumptions---and open
s up prospects for indirect detection of weakly interacting particles arou
nd stars. [Based on https://arxiv.org/abs/2006.12431 and https://arxiv.org
/abs/2008.08594\, and ongoing work.]\n
LOCATION:https://researchseminars.org/talk/nhetc/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jeff Dror (UC Santa Cruz)
DTSTART;VALUE=DATE-TIME:20210420T170000Z
DTEND;VALUE=DATE-TIME:20210420T180000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/9
DESCRIPTION:Title: Te
sting fundamental physics using pulsars\nby Jeff Dror (UC Santa Cruz)
as part of NHETC Seminar\n\n\nAbstract\nA pulsar is a star that can rotate
as fast as a thousand times per second\, with each rotation sending a bea
m of light at our telescopes. The arrival time of each pulse is dependent
on the Earth's motion\, opening an opportunity to search for gravitational
waves shaking the Earth with frequencies of O(year^-1). In this talk\, I
will show how these datasets can be used to probe fundamental physics focu
sing both on types of signals to search for as well as how recent developm
ents in machine learning can be employed to greatly expand the range of se
arches carried out by pulsar timing experiments. These searches are partic
ularly timely due to the recent detection of a correlated signal across ma
ny pulsars\, which may be our first glimpse of gravitational waves from su
permassive black hole mergers.\n
LOCATION:https://researchseminars.org/talk/nhetc/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jared Kaplan (Johns Hopkins University)
DTSTART;VALUE=DATE-TIME:20210126T183000Z
DTEND;VALUE=DATE-TIME:20210126T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/10
DESCRIPTION:Title: S
caling Laws in Machine Learning and GPT-3\nby Jared Kaplan (Johns Hopk
ins University) as part of NHETC Seminar\n\n\nAbstract\nA variety of recen
t works suggest that scaling laws are ubiquitous in machine learning. In
particular\, neural network performance obeys scaling laws with respect to
the number of parameters\, dataset size\, and the training compute budget
. I will explain these scaling laws\, and argue that they are both precis
e and very universal. Then I will explain how this line of thinking led t
o the GPT-3 language model\, and what it suggests for the future.\n
LOCATION:https://researchseminars.org/talk/nhetc/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Harikrishnan Ramani (Stanford University)
DTSTART;VALUE=DATE-TIME:20210209T183000Z
DTEND;VALUE=DATE-TIME:20210209T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/11
DESCRIPTION:Title: T
ackling energy deficits for dark matter detection\nby Harikrishnan Ram
ani (Stanford University) as part of NHETC Seminar\n\n\nAbstract\nModels s
uch as inelastic dark matter\, dark matter with large interactions with th
e standard model\, and dark matter with masses below 1 MeV are notoriously
difficult to detect in direct detection experiments owing to their inabil
ity to impart a large enough recoil energy in traditional dark matter expe
riments. In this talk\, I explore different strategies to attack this prob
lem. These include nuclear isomer batteries\, electric fields to accelerat
e milli-charge dark matter and atoms and molecules with small energy gaps.
\n
LOCATION:https://researchseminars.org/talk/nhetc/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emil Martinec (University of Chicago)
DTSTART;VALUE=DATE-TIME:20210413T170000Z
DTEND;VALUE=DATE-TIME:20210413T180000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/12
DESCRIPTION:Title: S
tringy Structure at the BPS Bound\nby Emil Martinec (University of Chi
cago) as part of NHETC Seminar\n\n\nAbstract\nWorldsheet string theory pai
nts a picture of BPS and near-BPS states of NS5-branes. We employ a class
of 1/2-BPS states having an exactly solvable worldsheet description in te
rms of gauged WZW models to explore the stringy properties of these states
. Consequences for black hole formation will also be discussed.\n
LOCATION:https://researchseminars.org/talk/nhetc/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brian Nord (Fermilab)
DTSTART;VALUE=DATE-TIME:20210504T170000Z
DTEND;VALUE=DATE-TIME:20210504T180000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/13
DESCRIPTION:Title: D
eeply Uncertain: (how) can we make deep learning tools trustworthy for sci
entific measurements?\nby Brian Nord (Fermilab) as part of NHETC Semin
ar\n\n\nAbstract\nArtificial Intelligence (AI) --- including machine learn
ing and deep learning --- refers to a set of techniques that rely primaril
y on the data itself for the construction of a quantitative model. AI has
been in development for about three quarters of a century\, but there has
been a recent resurgence in research and applications. This current (third
) wave of AI progress is marked by extraordinary results --- for example\,
in image analysis\, language translation\, and machine automation. Despit
e the modest definition of AI\, its potential to disrupt technologies\, ec
onomies\, society\, and even science is often presented as unmatched in mo
dern times. However\, along with the promise of AI\, there are significant
challenges to overcome to reach a degree of reliability that is on par wi
th more traditional modeling methods. \nIn particular\, uncertainty quanti
fication metrics derived from deep neural networks are yet to be made phys
ically interpretable. For example\, when one uses a convolutional neural n
etwork to measure values from an image (e.g.\, regression for galaxy prope
rties)\, the error estimates do not necessarily match those from an MCMC l
ikelihood fit. In this presentation\, I will discuss the landscape of unce
rtainty quantification in deep learning\, as well as some computational ex
periments in a physical context that demonstrate a mismatch between errors
derived directly from deep learning methods and those derived through tra
ditional error propagation. Before we can apply deep learning tools confid
ently for the direct measurement of physical properties\, we’ll need sta
tistically robust error estimation methods.\n
LOCATION:https://researchseminars.org/talk/nhetc/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tongyan Lin
DTSTART;VALUE=DATE-TIME:20210907T170000Z
DTEND;VALUE=DATE-TIME:20210907T180000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/14
DESCRIPTION:Title: D
ark matter direct detection with dielectrics\nby Tongyan Lin as part o
f NHETC Seminar\n\n\nAbstract\nDirect detection experiments are rapidly ad
vancing in the search for sub-GeV dark matter. As energy thresholds become
lower\, the many-body physics of a target material becomes especially imp
ortant in determining a dark matter signal. In this talk\, I will discuss
how dark matter interactions in dielectric materials can be understood in
terms of the dielectric response\, or energy loss function (ELF). This pro
vides a useful framework for dark matter direct detection and also allows
us to calculate some new effects. I will discuss various applications of t
his\, including screening effects for dark matter electron scattering\, ph
onon creation\, and the Migdal effect in semiconductors.\n
LOCATION:https://researchseminars.org/talk/nhetc/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shu-Heng Shao (YITP\, Stony Brook University)
DTSTART;VALUE=DATE-TIME:20210914T170000Z
DTEND;VALUE=DATE-TIME:20210914T180000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/15
DESCRIPTION:Title: O
n topological boundary conditions in 2+1d TQFT\nby Shu-Heng Shao (YITP
\, Stony Brook University) as part of NHETC Seminar\n\n\nAbstract\nA 2+1-d
imensional topological quantum field theory (TQFT) may or may not admit to
pological (gapped) boundary conditions. In this talk\, we consider obstruc
tions to the existence of a topological boundary condition from the "highe
r" central charges\, which have been introduced recently in the math liter
ature. In terms of these new obstructions\, we identify necessary and suff
icient conditions for the existence of a topological boundary in the case
of bosonic\, Abelian TQFTs\, providing an alternative to the identificatio
n of a Lagrangian subgroup. Our proof relies on general aspects of gauging
generalized global symmetries.\n
LOCATION:https://researchseminars.org/talk/nhetc/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Whiteson (University of California\, Irvine)
DTSTART;VALUE=DATE-TIME:20210921T170000Z
DTEND;VALUE=DATE-TIME:20210921T180000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/16
DESCRIPTION:Title: L
earning Particle Physics from Machines\nby Daniel Whiteson (University
of California\, Irvine) as part of NHETC Seminar\n\n\nAbstract\nRecent ad
vances in artificial intelligence offer opportunities to disrupt the tradi
tional strategies for discovery of new particles in high energy collisions
. I will describe the new machine-learning techniques\, explain why they
are particularly well suited for particle physics\, present selected resul
ts that demonstrate their new capabilities\, and present a strategy for tr
anslating their learned strategies into human understanding. \n\nBio: D
aniel Whiteson is a professor of experimental particle physics at the Univ
ersity of California\, Irvine\, and a fellow of the American Physical Soci
ety. He conducts research using the Large Hadron Collider at CERN. He rec
eived his PhD at Berkeley.\n
LOCATION:https://researchseminars.org/talk/nhetc/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John McGreevy (University of California\, San Diego)
DTSTART;VALUE=DATE-TIME:20210928T183000Z
DTEND;VALUE=DATE-TIME:20210928T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/17
DESCRIPTION:Title: F
ractons and Chern-Simons Theory\nby John McGreevy (University of Calif
ornia\, San Diego) as part of NHETC Seminar\n\n\nAbstract\nAfter discussin
g some reasons that fractons are interesting\, I will talk about a version
of dimensional deconstruction that produces 3+1d fracton phases. This con
struction provides examples beyond those known from solvable lattice model
s\, and a possible route to realize them in experiments.\n\nBased on 2010.
08917 with Xiuqi Ma\, Wilbur Shirley\, Meng Cheng\, Michael Levin and Xie
Chen.\n
LOCATION:https://researchseminars.org/talk/nhetc/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Harlow (MIT)
DTSTART;VALUE=DATE-TIME:20211012T160000Z
DTEND;VALUE=DATE-TIME:20211012T170000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/18
DESCRIPTION:Title: A
universal formula for the density of states in theories with finite-group
symmetry\nby Daniel Harlow (MIT) as part of NHETC Seminar\n\n\nAbstra
ct\nIn this paper we use Euclidean gravity to derive a simple formula for
the density of black hole microstates which transform in each irreducible
representation of any finite gauge group. Since each representation appear
s with nonzero density\, this\ngives a new proof of the completeness hypot
hesis for finite gauge fields. Inspired by the generality of the argument
we further propose that the formula applies at high energy in any quantum
field theory with a finite-group global symmetry\, and give some evidence
for this conjecture.\n
LOCATION:https://researchseminars.org/talk/nhetc/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Davide Gaiotto (Perimeter Institute)
DTSTART;VALUE=DATE-TIME:20211026T183000Z
DTEND;VALUE=DATE-TIME:20211026T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/19
DESCRIPTION:Title: G
iant gravitons in twisted holograpy\nby Davide Gaiotto (Perimeter Inst
itute) as part of NHETC Seminar\n\n\nAbstract\nI will demonstrate the emer
gence of bulk geometric structures in a simple\, essentially free\, toy mo
del for holography.\n
LOCATION:https://researchseminars.org/talk/nhetc/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ofri Telem (LBNL Physics Division)
DTSTART;VALUE=DATE-TIME:20211102T183000Z
DTEND;VALUE=DATE-TIME:20211102T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/20
DESCRIPTION:Title: M
onopole Catalysis From Scattering Amplitudes\nby Ofri Telem (LBNL Phys
ics Division) as part of NHETC Seminar\n\n\nAbstract\nUsing our novel cons
truction of the S-matrix for the scattering of electric and magnetic charg
es\, we address the notoriously confusing effect of Monopole Catalysis. In
particular\, we provide an on-shell derivation of the Rubakov-Callan effe
ct\, as well as address the famous “monopole unitarity paradox” - wher
e there seems to be no valid final state in the scattering of a positron w
ith a GUT monopole. Our proposed final state involves 3 fermions with tota
l J=0\, which conserve all SM quantum numbers and can escape the core by v
irtue of their entanglement with the monopole.\n
LOCATION:https://researchseminars.org/talk/nhetc/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brian Swingle (MIT)
DTSTART;VALUE=DATE-TIME:20211109T193000Z
DTEND;VALUE=DATE-TIME:20211109T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/21
DESCRIPTION:Title: H
ydrodynamics and the Spectral Form Factor\nby Brian Swingle (MIT) as p
art of NHETC Seminar\n\n\nAbstract\nEnsembles of quantum chaotic systems a
re expected to exhibit random matrix universality in their energy spectrum
. The presence of this universality can be diagnosed by looking for a line
ar in time 'ramp' in the spectral form factor\, but for realistic systems
this feature is typically only visible after a sufficiently long time. It
is important to understand the emergence of this universality and how it c
onnects to the larger body of phenomena associated with quantum chaos. Thi
s talk will present a hydrodynamic theory of the spectral form factor in s
ystems with slow modes. The formalism predicts the linear ramp at sufficie
ntly late time and gives a quantitative framework for computing the approa
ch to ramp.\n
LOCATION:https://researchseminars.org/talk/nhetc/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Katelin Schutz (McGill Space Institute)
DTSTART;VALUE=DATE-TIME:20211116T193000Z
DTEND;VALUE=DATE-TIME:20211116T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/22
DESCRIPTION:Title: A
strophysical plasmas\, phase space\, and searches for new particles\nb
y Katelin Schutz (McGill Space Institute) as part of NHETC Seminar\n\n\nAb
stract\nAstrophysical plasmas can be an abundant source of particles with
a small coupling to photons\, for instance in dark sectors with a kinetica
lly mixed U(1). In many situations\, the decay of plasmons (photons with a
n in-medium effective mass) is the most efficient process for generating n
ew kinds of particles. In this talk\, I will discuss two distinct examples
: the production of gravitationally bound particles in the sun and the fre
eze-in of dark matter in the early Universe. In the former case\, I will s
how how gravitationally bound particles from the sun may be detectable wit
h an experimental setup that coherently deflects the solar MCP wind\, gene
rating an oscillating electric field in a shielded detector. In the latter
case\, I will show that dark matter freeze-in from plasmon decay may be d
etectable through its cosmological clustering and through a drag effect im
parted on the photon-baryon fluid prior to recombination. If there is suff
icient time\, I will also discuss the detection of axion dark matter decay
that is stimulated by the synchrotron radiation coming from the plasma su
ffusing supernova remnants. In all of these examples\, the unique phase sp
ace of new particles provides the main observational handle for discovery.
\n
LOCATION:https://researchseminars.org/talk/nhetc/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoff Penington (UC Berkeley)
DTSTART;VALUE=DATE-TIME:20211130T193000Z
DTEND;VALUE=DATE-TIME:20211130T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/24
DESCRIPTION:Title: Q
uantum minimal surfaces from quantum error correction\nby Geoff Pening
ton (UC Berkeley) as part of NHETC Seminar\n\n\nAbstract\nWe show that com
plementary state-specific reconstruction of logical (bulk) operators is eq
uivalent to the existence of a quantum minimal surface prescription for ph
ysical (boundary) entropies. This significantly generalizes both sides of
an equivalence previously shown by Harlow\; in particular\, we do not requ
ire the entanglement wedge to be the same for all states in the code space
. In developing this theorem\, we construct an emergent bulk geometry for
general quantum codes\, defining "areas" associated to arbitrary logical s
ubsystems\, and argue that this definition is "functionally unique." We al
so formalize a definition of bulk reconstruction that we call "state-speci
fic product unitary" reconstruction. This definition captures the quantum
error correction (QEC) properties present in holographic codes and has pot
ential independent interest as a very broad generalization of QEC\; it inc
ludes most traditional versions of QEC as special cases. Our results exten
d to approximate codes\, and even to the "non-isometric codes" that seem t
o describe the interior of a black hole at late times.\n
LOCATION:https://researchseminars.org/talk/nhetc/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rebecca Leane (SLAC)
DTSTART;VALUE=DATE-TIME:20211207T193000Z
DTEND;VALUE=DATE-TIME:20211207T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/25
DESCRIPTION:Title: D
etecting Dark Matter in Celestial Bodies\nby Rebecca Leane (SLAC) as p
art of NHETC Seminar\n\n\nAbstract\nStars and planets can be ideal playgro
unds to discover dark matter. In this talk\, I will review a range of dark
matter searches using celestial objects\, including neutron stars\, exopl
anets\, solar-system planets\, and our Sun. I will discuss different searc
h strategies\, their opportunities and limitations\, and the interplay of
regimes where different celestial objects are optimal detectors.\n
LOCATION:https://researchseminars.org/talk/nhetc/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Patrick Draper (University of Illinois)
DTSTART;VALUE=DATE-TIME:20211005T183000Z
DTEND;VALUE=DATE-TIME:20211005T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/26
DESCRIPTION:Title: T
he CKN Bound and Particle Physics\nby Patrick Draper (University of Il
linois) as part of NHETC Seminar\n\n\nAbstract\nThe holographic principle
implies that quantum field theory overcounts the number of independent deg
rees of freedom in quantum gravity. An argument due to Cohen\, Kaplan\, an
d Nelson (CKN) suggests that the number of degrees of freedom well-describ
ed by QFT is even smaller than required by holographic bounds\, and CKN in
terpreted this result as indicative of a correlation between the UV and IR
cutoffs on QFT. We consider an alternative interpretation in which the QF
T degrees of freedom are depleted as a function of scale\, and we use a si
mple recipe to estimate the impact of depleted densities of states on prec
ision observables. Although these observables are not sensitive to the lev
el of depletion motivated by gravitational considerations\, the phenomenol
ogical exercises also provide an interesting test of QFT that is independe
nt of underlying quantum gravity assumptions. A depleted density of states
can also render the QFT vacuum energy UV-insensitive\, reconciling the su
ccess of QFT in describing ordinary particle physics processes and its app
arent failure in predicting the cosmological constant.\n
LOCATION:https://researchseminars.org/talk/nhetc/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Siddharth Mishra-Sharma (MIT)
DTSTART;VALUE=DATE-TIME:20211019T183000Z
DTEND;VALUE=DATE-TIME:20211019T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/27
DESCRIPTION:Title: U
sing machine learning to look for dark matter in the Galactic Center\, the
Milky Way halo\, and other galaxies\nby Siddharth Mishra-Sharma (MIT)
as part of NHETC Seminar\n\n\nAbstract\nAdvancements in machine learning
have enabled new ways of doing inference on forward models defined through
complex\, high-dimensional simulations. After briefly motivating their us
e in the cosmological context\, I will present applications of these simul
ation-based inference methods to three separate astrophysical systems with
the goal of looking for signatures of dark matter. First\, I will describ
e how they can be used to combine information from thousands of strong gra
vitational lensing systems in a principled way in order to extract the pop
ulation properties of dark matter. Then\, I will quantify their sensitivit
y to the collective imprint of dark matter subhalos in our own Galaxy on t
he measured motions of background luminous celestial objects. Finally\, I
will present an application to the Galactic Center gamma-ray excess\, wher
e the fact that our method can extract more information from the gamma-ray
dataset than is possible with traditional techniques can be used to more
robustly characterize the nature of the excess and constrain its dark matt
er properties.\n
LOCATION:https://researchseminars.org/talk/nhetc/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juven Wang (Harvard)
DTSTART;VALUE=DATE-TIME:20211123T193000Z
DTEND;VALUE=DATE-TIME:20211123T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/28
DESCRIPTION:Title: Q
uantum Criticality Beyond the Standard Model and Ultra Unification\nby
Juven Wang (Harvard) as part of NHETC Seminar\n\n\nAbstract\nWe propose a
theory [arXiv:2012.15860] beyond the Standard Model (SM) and Grand Unific
ation (GUT) with 15n Weyl fermions by adding new gapped Topological Phase
Sectors based on nonperturbative global anomaly cancellations and cobordis
m constraints (especially from the baryon minus lepton number B − L \, t
he electroweak hypercharge Y\, and the Z_{16} class mixed gauge-gravitatio
nal anomaly). Gapped topological phase sectors are constructed via symmetr
y extension (in contrast with the Anderson-Higgs symmetry breaking)\, whos
e low energy contains unitary Lorentz invariant topological quantum field
theories (TQFTs): either (3+1)d noninvertible TQFT\, or (4+1)d invertible
or noninvertible TQFT (short-range or long-range entangled gapped phase).
Alternatively\, there could also be right-handed neutrinos\, or gapless un
particle conformal field theories\, or their combinations to altogether ca
ncel the mixed gauge-gravitational anomaly. We also introduce an alternati
ve view [arXiv:2106.16248] that the SM is a low-energy quantum vacuum aris
ing from various neighbor GUT vacua competition in an immense quantum phas
e diagram. In particular\, we demonstrate how the su(3)×su(2)×u(1) SM wi
th 16n Weyl fermions arose near the quantum criticality between the compet
ition of Georgi-Glashow su(5) model and Pati-Salam su(4)×su(2)×su(2) mod
el. Moreover\, to manifest a Beyond-the-Standard-Model (BSM) and Beyond-La
ndau-Ginzburg deconfined quantum criticality between Georgi-Glashow and Pa
ti-Salam models\, we introduce a parent effective field theory of a modifi
ed so(10) GUT (with a Spin(10) gauge group) plus a new 4d discrete torsion
class of Wess-Zumino-Witten-like term that saturates a Z_2 class global m
ixed gauge-gravity anomaly captured by a 5d invertible topological field t
heory w2w3(TM)=w2w3(VSO(10)). We show new fractionalized excitations of Co
lor-Flavor separation\, and gauge enhancement including a Dark Gauge force
sector\, or gauge-enhanced 4d criticality as a boundary criticality such
that only appropriately gauge enhanced dynamical GUT gauge fields can prop
agate into an extra-dimensional 5d bulk.\n\nThe talk is mainly based on ar
Xiv:2012.15860\, arXiv:2106.16248\, and arXiv:2111.10369 (with Yi-Zhuang Y
ou).\n
LOCATION:https://researchseminars.org/talk/nhetc/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anton Kapustin (Caltech)
DTSTART;VALUE=DATE-TIME:20220222T193000Z
DTEND;VALUE=DATE-TIME:20220222T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/29
DESCRIPTION:Title: E
quivariant Berry phase for many-body quantum lattice systems\nby Anton
Kapustin (Caltech) as part of NHETC Seminar\n\n\nAbstract\nBerry phase as
originally defined makes sense only for quantum systems with a finite-dim
ensional Hilbert space. However\, it does have important generalizations t
o many-body systems. In this talk I will describe some generalizations of
the Berry phase to the case of quantum lattice systems in infinite volume.
The Hall conductance and its nonabelian versions emerge as special cases.
The results can be viewed as a generalizations of the von Neumann - Wigne
r theorem on level crossing in quantum systems.\n
LOCATION:https://researchseminars.org/talk/nhetc/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hank Lamm (Fermilab)
DTSTART;VALUE=DATE-TIME:20220201T193000Z
DTEND;VALUE=DATE-TIME:20220201T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/30
DESCRIPTION:Title: Q
uantum Computing for Quantum Field Theories\nby Hank Lamm (Fermilab) a
s part of NHETC Seminar\n\n\nAbstract\nThe advent of quantum computation p
resents the opportunity to solve questions in physics which are inaccessib
le to classical computation such as real-time evolution and the equation o
f state at finite density. In order to take advantage of this new resource
\, a number of theoretical and computational hurdles will need to be addre
ssed. In this talk\, I will discuss the state of the art research being p
erformed in quantum field theory and outstanding questions that require ou
r attention going forward\, focusing on digitization of lattice gauge theo
ries and extracting physical results that demonstrate practical quantum ad
vantage.\n
LOCATION:https://researchseminars.org/talk/nhetc/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Graham White (University of Tokyo)
DTSTART;VALUE=DATE-TIME:20220215T213000Z
DTEND;VALUE=DATE-TIME:20220215T223000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/31
DESCRIPTION:Title: A
rchaeology on the origin of matter\nby Graham White (University of Tok
yo) as part of NHETC Seminar\n\n\nAbstract\nOne of the most convincing rea
sons to expect physics beyond\nthe Standard model is the inbalance between
matter and anti-matter. Some\nfantastic paradigms exist that can be probe
d at a low scale including\nelectroweak baryogenesis\, mesogenesis and res
onant leptogenesis. While\nthese paradigms or worthy of dedicated attentio
n\, the elephant in the\nroom is that there are two paradigms that are ver
y minimal and involve\nphysics at scales we cannot possibly reach with Ear
th based colliders in\nour life time. I will first discuss the nightmare s
cenario of thermal\nleptogenesis implemented with no BSM particle content
beyond sterile\nneutrinos and an inflaton. In this case\, measurements of
the top and\nHiggs mass along with inflationary observables can shed some
light on\nthe plausibility\, or lack thereof\, of vanilla leptogenesis. I
will then\ndiscuss the GUT leptogenesis and Affleck Dine baryogenesis. I a
rgue in\nboth these cases there are generic predictions of a primordial\ng
ravitational wave background that can be measured today. The presence\nof
such a signal would lend plausibility to one of these scenarios.\nFinally
I discuss the discriminating power of GWs in discerning the\nsymmetry bre
aking path through the variable signals of hybrid defects.\n
LOCATION:https://researchseminars.org/talk/nhetc/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Clara Murgui (Caltech)
DTSTART;VALUE=DATE-TIME:20220301T193000Z
DTEND;VALUE=DATE-TIME:20220301T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/32
DESCRIPTION:Title: D
ark Unification: a UV-complete Theory of Asymmetric Dark Matter\nby Cl
ara Murgui (Caltech) as part of NHETC Seminar\n\n\nAbstract\nMotivated by
the observed ratio of dark matter to baryon mass densities\, which is arou
nd a factor 5\, we propose a theory of dark-color unification. In this the
ory\, the dark to visible baryon masses are fixed by the ratio of dark to
visible confinement scales\, which are determined to be nearby in mass thr
ough the unification of the dark and visible gauge theories at a high scal
e. Together with a mechanism for darko-baryo-genesis\, which arises natura
lly from the grand unification sector\, the mass densities of the two sect
ors must be nearby\, explaining the observed mass density of dark matter.
We focus on the simplest possible example of such a theory\, where Standar
d Model color SU(3)c is unified with dark color SU(2)D into SU(5) at an in
termediate scale of around 10^8 -10^9 GeV. The dark baryon consists of two
dark quarks in an isotriplet configuration. There are a range of importan
t cosmological\, astrophysical and collider signatures to explore\, includ
ing dark matter self-interactions\, early matter domination from the dark
hadrons\, gravitational wave signatures from the hidden sector phase trans
ition\, contributions to flavor observables\, as well as Hidden Valley-lik
e signatures at colliders.\n
LOCATION:https://researchseminars.org/talk/nhetc/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tudor Dimofte (UC Davis and University of Edinburgh)
DTSTART;VALUE=DATE-TIME:20220308T193000Z
DTEND;VALUE=DATE-TIME:20220308T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/33
DESCRIPTION:Title: A
QFT for non-semisimple TQFT\nby Tudor Dimofte (UC Davis and Universit
y of Edinburgh) as part of NHETC Seminar\n\n\nAbstract\nTopological twists
of 3d N=4 gauge theories naturally give rise to non-semisimple 3d TQFT's.
In mathematics\, prototypical examples of the latter were constructed in
the 90's (by Lyubashenko and others) from representation categories of sma
ll quantum groups at roots of unity\; they were recently generalized in wo
rk of Costantino-Geer-Patureau Mirand and collaborators. I will introduce
a family of physical 3d quantum field theories that (conjecturally) reprod
uce these classic non-semisimple TQFT's. The physical theories combine Che
rn-Simons-like and 3d N=4-like sectors. They are also related to Feigin-Ti
punin vertex algebras\, much the same way that Chern-Simons theory is rela
ted to WZW vertex algebras.\n(Based on work with T. Creutzig\, N. Garner\,
and N. Geer.)\n
LOCATION:https://researchseminars.org/talk/nhetc/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Greg Yang (Microsoft Research)
DTSTART;VALUE=DATE-TIME:20220322T183000Z
DTEND;VALUE=DATE-TIME:20220322T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/34
DESCRIPTION:Title: R
enormalizing the Optimal Hyperparameters of a Neural Network\nby Greg
Yang (Microsoft Research) as part of NHETC Seminar\n\n\nAbstract\nHyperpar
ameter tuning in deep learning is an expensive process\, prohibitively so
for neural networks (NNs) with billions of parameters that often can only
be trained once. We show that\, in the recently discovered Maximal Update
Parametrization (μP)\, many optimal hyperparameters remain stable even as
model size changes. Using this insight\, for example\, we are able to re
-tune the 6.7-billion-parameter model of GPT-3 and obtain performance comp
arable to the 13-billion-parameter model of GPT-3\, effectively doubling t
he model size.\n\nIn this context\, there is a rich analogy we can make to
Wilsonian effective field theory. For example\, if “coupling constants
” in physics correspond to “optimal hyperparameters” in deep learnin
g and “cutoff scale” corresponds to “model size”\, then we can say
“μP is a renormalizable theory of neural networks.” We finish by for
mulating the question of whether there is a “Grand Unifying Theory” of
neural networks at scale that can inform our quest toward general intelli
gence.\n
LOCATION:https://researchseminars.org/talk/nhetc/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andy Neitzke (Yale University)
DTSTART;VALUE=DATE-TIME:20220329T183000Z
DTEND;VALUE=DATE-TIME:20220329T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/35
DESCRIPTION:Title: D
ifferential equations and deformations of supersymmetric QFT\nby Andy
Neitzke (Yale University) as part of NHETC Seminar\n\n\nAbstract\nThere is
a connection between N=2 supersymmetric field theory in four dimensions a
nd the theory of linear differential and difference equations with meromor
phic coefficients. This connection is surprisingly rich\, and has been stu
died by many different authors from different perspectives. One way of und
erstanding it is as an instance of the general phenomenon that turning on
Omega-background naturally quantizes algebraic structures in the operator
algebras of supersymmetric QFT. I will recall this connection and describe
some of its uses\, along with some recent and ongoing extensions of the s
tory.\n
LOCATION:https://researchseminars.org/talk/nhetc/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ian Moult (Yale University)
DTSTART;VALUE=DATE-TIME:20220405T183000Z
DTEND;VALUE=DATE-TIME:20220405T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/36
DESCRIPTION:Title: C
onformal Colliders Meet the LHC\nby Ian Moult (Yale University) as par
t of NHETC Seminar\n\n\nAbstract\nJets of hadrons produced at high-energy
colliders provide experimental access to the dynamics of asymptotically fr
ee quarks and gluons and their confinement into hadrons. Motivated by rece
nt developments in conformal field theory\, we propose a reformulation of
jet substructure as the study of correlation functions of a specific class
of light-ray operators and their associated operator product expansion (O
PE). We show that multi-point correlation functions of these operators can
be measured in real LHC data\, allowing us to experimentally verify prope
rties of the light-ray OPE. We then discuss how this reformulation provide
s new ways of experimentally studying the Standard Model at colliders\, as
well as new theoretical techniques for performing calculations in QCD.\n
LOCATION:https://researchseminars.org/talk/nhetc/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Du Pei (Harvard)
DTSTART;VALUE=DATE-TIME:20220412T183000Z
DTEND;VALUE=DATE-TIME:20220412T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/37
DESCRIPTION:Title: H
olomorphic CFTs and topological modular forms\nby Du Pei (Harvard) as
part of NHETC Seminar\n\n\nAbstract\nThe theory of topological modular for
ms leads to many interesting constraints and predictions for two-dimension
al quantum field theories. In this talk\, I will show that a conjecture by
Segal\, Stolz and Teichner requires the constant term of the partition fu
nction of a bosonic holomorphic CFTs to be divisible by specific integers
determined by the central charge. We verify this constraint in large class
es of physical examples\, and rule out the existence of an infinite set of
"extremal CFTs"\, including those with central charges c = 48\, 72\, 96 a
nd 120.\n
LOCATION:https://researchseminars.org/talk/nhetc/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joshua Isaacson (Fermilab)
DTSTART;VALUE=DATE-TIME:20220419T183000Z
DTEND;VALUE=DATE-TIME:20220419T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/38
DESCRIPTION:Title: H
ow to measure M_W: A theory perspective\nby Joshua Isaacson (Fermilab)
as part of NHETC Seminar\n\n\nAbstract\nWith the recent CDF-II W mass mea
surement\, many questions have arisen about the accuracy and procedure of
extracting the W mass. In this talk\, I will cover the details of the ResB
os calculation used by the CDF experiment\, along with details on the proc
edure of extracting the W mass and the associated theory uncertainties.\n
LOCATION:https://researchseminars.org/talk/nhetc/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pietro Longhi (Uppsala University)
DTSTART;VALUE=DATE-TIME:20220426T183000Z
DTEND;VALUE=DATE-TIME:20220426T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/39
DESCRIPTION:Title: S
tudies of five-dimensional BPS spectra and applications to enumerative geo
metry\nby Pietro Longhi (Uppsala University) as part of NHETC Seminar\
n\n\nAbstract\nThe framework of spectral networks was introduced in physic
s as a way to compute BPS states of 4d N=2 gauge theories. In this talk I
will review an extension of this framework\, known as exponential networks
\, which arises in the study of 5d N=1 BPS states. Geometric engineering c
onnects 5d N=1 BPS spectra to enumerative invariants of certain Calabi-Yau
threefolds\, I will review the computation of old and new results in the
setting of local toric threefolds. I will also sketch a new perspective on
this framework\, which elucidates the geometric meaning of the invariants
computed by networks\, in terms of elementary data of A-branes in the mir
ror geometry\, recovering an old conjecture of Joyce.\n
LOCATION:https://researchseminars.org/talk/nhetc/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anja Butter (ITP in Heidelberg)
DTSTART;VALUE=DATE-TIME:20220503T183000Z
DTEND;VALUE=DATE-TIME:20220503T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/40
DESCRIPTION:Title: N
ormalizing Flows for LHC Theory\nby Anja Butter (ITP in Heidelberg) as
part of NHETC Seminar\n\n\nAbstract\nOver the next years\, measurements a
t the LHC and the HL-LHC will provide us with a wealth of new data. The be
st hope to answer fundamental questions\, like the nature of dark matter\,
is to adopt big data techniques in simulations and analyses to extract al
l relevant information. On the theory side\, LHC physics crucially relies
on our ability to simulate events efficiently from first principles. These
simulations will face unprecedented precision requirements to match the e
xperimental accuracy. Innovative ML techniques like generative models can
help us overcome limitations from the high dimensionality of the phase spa
ce. Such networks can be employed to directly simulate events or to suppor
t first principle calculations like multi-loop amplitudes. Since neural ne
tworks can be inverted\, they open new avenues in LHC analyses.\n
LOCATION:https://researchseminars.org/talk/nhetc/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dalimil Mazac (IAS)
DTSTART;VALUE=DATE-TIME:20220208T193000Z
DTEND;VALUE=DATE-TIME:20220208T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/41
DESCRIPTION:Title: A
utomorphic Spectra and the Conformal Bootstrap\nby Dalimil Mazac (IAS)
as part of NHETC Seminar\n\n\nAbstract\nI will explain that the spectral
geometry of hyperbolic manifolds provides a remarkably faithful model of t
he modern conformal bootstrap. In particular\, to each hyperbolic D-manifo
ld\, one can associate a Hilbert space of local operators\, which is a uni
tary representation of a conformal group. The local operators live in an e
mergent (D-1)-dimensional spacetime. The scaling dimensions of the operato
rs are related to the eigenvalues of the Laplacian on the manifold. The op
erators satisfy an operator product expansion. Finally\, one can define th
eir correlation functions and derive bootstrap equations constraining the
spectrum. As an application\, I will use conformal bootstrap techniques to
derive upper bounds on the lowest positive eigenvalue of the Laplacian on
closed hyperbolic surfaces and 2-orbifolds. In a number of notable cases\
, the bounds are nearly saturated by known surfaces and orbifolds. For ins
tance\, the bound on all genus-2 surfaces is λ1≤3.8388976481\, while th
e Bolza surface has λ1≈3.838887258. The talk will be based on https://a
rxiv.org/abs/2111.12716\, which is joint work with P. Kravchuk and S. Pal.
\n
LOCATION:https://researchseminars.org/talk/nhetc/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Peizhi Du (Stony Brook University)
DTSTART;VALUE=DATE-TIME:20220315T183000Z
DTEND;VALUE=DATE-TIME:20220315T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/42
DESCRIPTION:Title: N
ew backgrounds and new ideas for sub-GeV dark matter direct detection\
nby Peizhi Du (Stony Brook University) as part of NHETC Seminar\n\n\nAbstr
act\nProbing sub-GeV dark matter requires designing low threshold detector
s and understanding backgrounds. In this talk I will address these two iss
ues. First\, we point out several unexplored low-energy backgrounds in sub
-GeV dark matter searches\, which arise from high-energy particles of cosm
ic or radioactive origin that interact with detector materials. In this ta
lk\, I will focus on Cherenkov radiation and luminescence from electron-ho
le pair recombination. We demonstrate that these processes provide plausib
le explanations of the observed events at SENSEI and SuperCDMS HVeV. Secon
d\, we propose a new idea of probing light dark matter using doped semicon
ductors. Dopants in semiconductors form energy levels that are tens of meV
below the conduction band or above the valence band. These materials can
be new detector targets for dark matter scattering with a threshold of ten
s of meV\, which can probe dark matter masses down to tens of keV.\n
LOCATION:https://researchseminars.org/talk/nhetc/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Prasanth Shyamsundar (Fermilab)
DTSTART;VALUE=DATE-TIME:20220517T183000Z
DTEND;VALUE=DATE-TIME:20220517T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/43
DESCRIPTION:Title: C
onstructing sensitive and robust collider observables with machine learnin
g\nby Prasanth Shyamsundar (Fermilab) as part of NHETC Seminar\n\n\nAb
stract\nI will discuss some concluded and ongoing work on constructing\, u
sing machine learning\, sensitive low-dimensional variables for use in col
lider data analyses. I will also briefly discuss the robustness offered by
the technique against unknown and unquantified errors in the simulation m
odels.\n
LOCATION:https://researchseminars.org/talk/nhetc/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sameer Murthy (King's College London)
DTSTART;VALUE=DATE-TIME:20220920T183000Z
DTEND;VALUE=DATE-TIME:20220920T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/44
DESCRIPTION:Title: G
iant gravitons in gauge theory\nby Sameer Murthy (King's College Londo
n) as part of NHETC Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anna Golubeva (MIT)
DTSTART;VALUE=DATE-TIME:20220927T183000Z
DTEND;VALUE=DATE-TIME:20220927T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/45
DESCRIPTION:Title: O
n the fundamental role of sparsity in machine learning\nby Anna Golube
va (MIT) as part of NHETC Seminar\n\n\nAbstract\nSparsity and neural-netwo
rk pruning have become indispensable tools in applied machine learning to
alleviate the computational demands of ever larger models. While the numbe
r of empirical works in this field has exploded in recent years\, bringing
out a variety of pruning techniques\, finding sparse solutions at initial
ization remains a challenge. Moreover\, a theoretical understanding of the
very existence of sparse solutions in neural networks is lacking. In this
talk\, I will discuss the most interesting open questions in this field a
nd present some of our recent work combining theoretical and experimental
approaches to tackle them.\n
LOCATION:https://researchseminars.org/talk/nhetc/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ben Lillard (University of Oregon)
DTSTART;VALUE=DATE-TIME:20221004T183000Z
DTEND;VALUE=DATE-TIME:20221004T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/46
DESCRIPTION:by Ben Lillard (University of Oregon) as part of NHETC Seminar
\n\n\nAbstract\nOrganic scintillators are a promising avenue for the direc
t detection of sub-GeV dark matter (DM). With eV-scale excitation energies
that rival the sensitivity of semiconductor targets\, they can be produce
d in bulk and purified relatively inexpensively. A low-background kilogram
-size scintillator target could achieve world-leading sensitivity to sub-G
eV dark matter. Crystal scintillators also provide a new capability: the d
ark matter scattering rate depends on the orientation of the crystal\, whi
ch varies with the Earth's rotation over the course of a sidereal day (23.
93 hours). The discovery of such a signal would be a clear sign of new phy
sics. While most studies of daily modulation focus on DM-electron scatteri
ng\, recent results for diatomic molecules suggest that DM-nuclear scatter
ing can also provide a detectable\, directional-dependent signal. In this
talk I discuss both kinds of DM models\, the realistic prospects for cryst
alline detectors in the near future\, and the remaining theoretical work t
hat needs to be done for nuclear scattering in more complicated molecules.
\n
LOCATION:https://researchseminars.org/talk/nhetc/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Clay Cordova (University of Chicago)
DTSTART;VALUE=DATE-TIME:20221011T183000Z
DTEND;VALUE=DATE-TIME:20221011T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/47
DESCRIPTION:by Clay Cordova (University of Chicago) as part of NHETC Semin
ar\n\n\nAbstract\nWe elucidate the fate of classical symmetries which suff
er from abelian Adler-Bell-Jackiw anomalies. Instead of being completely d
estroyed\, these symmetries survive as non-invertible topological global s
ymmetry defects with worldvolume anyon degrees of freedom that couple to t
he bulk through a magnetic one-form global symmetry as in the fractional h
all effect. These non-invertible chiral symmetries imply selection rules o
n correlation functions and arise in familiar models of massless quantum e
lectrodynamics and models of axions (as well as their non-abelian generali
zations). When the associated bulk magnetic one-form symmetry is broken by
the propagation of dynamical magnetic monopoles\, the selection rules of
the non-invertible chiral symmetry defects are violated non-perturbatively
. This leads to technically natural exponential hierarchies in axion poten
tials and fermion masses.\n
LOCATION:https://researchseminars.org/talk/nhetc/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eliezer Rabinovici (CERN)
DTSTART;VALUE=DATE-TIME:20221018T183000Z
DTEND;VALUE=DATE-TIME:20221018T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/48
DESCRIPTION:Title: P
ersistent Spontaneous Symmetry Breaking at High Temperatures\nby Eliez
er Rabinovici (CERN) as part of NHETC Seminar\n\n\nAbstract\nI will descri
be the results of a series of works in which we have found systems for whi
ch Spontaneous Symmetry Breaking(SSB) persists to very high temperatures.
\nThe systems involve Conformal Field Theories of scalars in fractional di
mensions 3F
actorization and Global symmetries in holography\nby Lorenzo Di Pietro
(UNITS) as part of NHETC Seminar\n\n\nAbstract\nBased on 2203.09537. In t
he context of toy models of holography arising from 3d Chern-Simons theory
\, I will describe an approach in which\, rather than summing over bulk ge
ometries\, one gauges a one-form global symmetry of the bulk theory. This
ensures that the bulk theory has no global symmetries\, and it makes the p
artition function on spacetimes with boundaries coincide with that of a mo
dular-invariant 2d CFT on the boundary. In particular\, on wormhole geomet
ries one finds a factorized answer for the partition function.\n
LOCATION:https://researchseminars.org/talk/nhetc/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Kutasov (University of Chicago)
DTSTART;VALUE=DATE-TIME:20221101T183000Z
DTEND;VALUE=DATE-TIME:20221101T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/50
DESCRIPTION:Title: S
mall Black Holes in String Theory\nby David Kutasov (University of Chi
cago) as part of NHETC Seminar\n\n\nAbstract\nI will describe some recent
work on Euclidean Schwarzschild black holes in d+1 dimensional flat spacet
ime\, in the limit where their Hawking temperature approaches the Hagedorn
temperature. This leads to new conformal field theories\, enhanced symmet
ry at the Hagedorn temperature\, and relations to earlier work on black ho
les at large d. If there is time\, I will also discuss an open string anal
og of this problem\, that exhibits similar phenomena.\n
LOCATION:https://researchseminars.org/talk/nhetc/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthew Bullimore (Durham University)
DTSTART;VALUE=DATE-TIME:20221108T193000Z
DTEND;VALUE=DATE-TIME:20221108T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/51
DESCRIPTION:Title: N
on-invertible symmetry and higher representation theory\nby Matthew Bu
llimore (Durham University) as part of NHETC Seminar\n\n\nAbstract\nThe pa
st year has seen an explosion in constructions of non-invertible symmetrie
s in quantum field theories in dimension greater than two\, such as gaugin
g discrete symmetries with mixed ’t Hooft anomalies\, gauging non-normal
subgroups of discrete symmetries\, higher gauging and condensations\, and
duality defects. I’ll present a common framework for such constructions
based on higher representation theory\, which describes higher dimensiona
l analogues of topological Wilson lines. Based on joint work with Thomas B
artsch\, Andrea Ferrari and Jamie Pearson.\n
LOCATION:https://researchseminars.org/talk/nhetc/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shu-Heng Shao (Stony Brook University)
DTSTART;VALUE=DATE-TIME:20221115T193000Z
DTEND;VALUE=DATE-TIME:20221115T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/52
DESCRIPTION:Title: N
on-invertible Symmetries in Nature\nby Shu-Heng Shao (Stony Brook Univ
ersity) as part of NHETC Seminar\n\n\nAbstract\nI will talk about non-inve
rtible global symmetries in QED and QCD\, and how the neutral pion decay r
ate can be determined from matching this new global symmetry. I will then
discuss a non-invertible 1-form symmetry from the anomalous Gauss law in a
xion-Maxwell theory.\n
LOCATION:https://researchseminars.org/talk/nhetc/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joshua Foster (MIT)
DTSTART;VALUE=DATE-TIME:20221122T193000Z
DTEND;VALUE=DATE-TIME:20221122T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/53
DESCRIPTION:Title: L
umped Element Axion Detection at All Frequencies\nby Joshua Foster (MI
T) as part of NHETC Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Keisuke Harigaya (University of Chicago)
DTSTART;VALUE=DATE-TIME:20221129T193000Z
DTEND;VALUE=DATE-TIME:20221129T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/54
DESCRIPTION:Title: C
osmology of Axion Rotation\nby Keisuke Harigaya (University of Chicago
) as part of NHETC Seminar\n\n\nAbstract\nWe will introduce new cosmologic
al dynamics of the QCD axion\, where the axion field rotates in field spac
e. Axion dark matter may be produced from the kinetic energy of the rotati
on and the required axion decay constant is much below the prediction of t
he conventional evolutions. The angular momentum of the rotation is transf
erred into baryon asymmetry through baryon number violating interactions.
We discuss the electroweak sphaleron process and some beyond-standard mode
l processes and predictions on the parameters of each theory.\n
LOCATION:https://researchseminars.org/talk/nhetc/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Isabel Garcia Garcia (University of California - Santa Barbara)
DTSTART;VALUE=DATE-TIME:20221206T193000Z
DTEND;VALUE=DATE-TIME:20221206T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/55
DESCRIPTION:Title: T
he Rocket Science of Bubble Walls\nby Isabel Garcia Garcia (University
of California - Santa Barbara) as part of NHETC Seminar\n\n\nAbstract\nCo
smological phase transitions that proceed via nucleation of bubbles are a
well-motivated possibility both in minimal extensions of the Standard Mode
l as well as in more general hidden sectors with their own dynamics. Such
an event produces a stochastic background of gravitational radiation that
could be observed by current and future observatories. That said\, our abi
lity to extract any detailed information about the underlying dynamics fro
m such an observation is extremely limited\, and highlights the necessity
of (i) better understanding the dynamics of bubble walls in the early Univ
erse\, given their impact on the high-frequency shape of the signal\, and
(ii) exploring complementary probes of an observable gravitational wave ba
ckground.\n\nIn this talk\, I will discuss the dynamics of expanding vacuu
m bubbles in the presence of massive vectors (a.k.a. dark photons) that ga
in mass across the interface -- with a special focus on the well-motivated
benchmark where the dark photons furnish the dark matter. I will argue th
e existence of a transient kinematic regime during which the wall behaves
as an (imperfect) mirror of longitudinal -- but not transverse -- modes. M
ost notably\, this leads to a new source of pressure on the expanding inte
rface that can prevent the accelerated expansion of the bubble walls. Inst
ead of accelerating the interface\, the difference in vacuum energy densit
y across the wall goes into making a fraction of the dark photons relativi
stic\, turning them into dark radiation. The corresponding value of \\Delt
a N_eff is determined by the strength of the phase transition and the epoc
h at which the transition takes place. Current \\Delta N_eff constraints c
an rule out phase transitions with strength \\alpha \\simeq 0.1\, whereas
CMB S-4 measurements will probe scenarios down to \\alpha = 0.01 for all r
elevant frequencies.\n\nThis talk is based on arXiv:2212.xxxxx in collabor
ation with Giacomo Koszegi and Rudin Petrossian-Byrne.\n
LOCATION:https://researchseminars.org/talk/nhetc/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikita Nekrasov (Stony Brook University)
DTSTART;VALUE=DATE-TIME:20220929T180000Z
DTEND;VALUE=DATE-TIME:20220929T190000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/56
DESCRIPTION:Title: O
ne flew over the QQ-nest\nby Nikita Nekrasov (Stony Brook University)
as part of NHETC Seminar\n\n\nAbstract\nI will discuss the recent progress
in Omega-deformed N=2 d=4 supersymmetric quiver theories of A-type with A
-type gauge group\, in the presence of various arrangements of surface def
ects. According to the BPS/CFT dictionary their expectation values are giv
en by the conformal blocks of some (analytically continued) CFT\, and\, at
the same time\, by the matrix elements of quantum XXX spin chains. Using
the qq-characters I derive (as opposed to postulate) the Q{\\tilde Q}-syst
em and the Lax operators\, filling some gaps in the 30 year cycle of ideas
connecting supersymmetry and integrability.\n
LOCATION:https://researchseminars.org/talk/nhetc/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Netta Engelhardt (MIT)
DTSTART;VALUE=DATE-TIME:20221110T190000Z
DTEND;VALUE=DATE-TIME:20221110T200000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/57
DESCRIPTION:Title: N
on-Isometric Codes\, Complexity\, and the Black Hole Information Paradox\nby Netta Engelhardt (MIT) as part of NHETC Seminar\n\n\nAbstract\nThis
talk focuses on recent progress on the role of computational complexity i
n the black hole information paradox. I will describe quantum code models
that settle the tension between two conflicting calculations of the entrop
y of Hawking radiation within semiclassical gravity: the standard “Hawki
ng” calculation and the quantum extremal surface calculation. The critic
al aspect of the construction involves a complexity bound on the validity
of effective field theory\, and I will discuss applications of this from t
he geometric perspective of holography as well as computationally bounded
quantum learning.\n
LOCATION:https://researchseminars.org/talk/nhetc/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seminar is Cancelled: Gabriel Wong (Harvard CMSA)
DTSTART;VALUE=DATE-TIME:20221201T190000Z
DTEND;VALUE=DATE-TIME:20221201T200000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/58
DESCRIPTION:Title: S
eminar is Cancelled: Generalized entropy in topological string theory
\nby Seminar is Cancelled: Gabriel Wong (Harvard CMSA) as part of NHETC S
eminar\n\n\nAbstract\nSeminar is Cancelled: The holographic entanglement
entropy formula identifies the generalized entropy of the bulk AdS spaceti
me with the entanglement entropy of the boundary CFT. However the bulk mic
rostate interpretation of the generalized entropy remains poorly understoo
d. Progress along this direction requires a definition of Hilbert space fa
ctorization and entanglement entropy in the bulk closed string theory. A
s a toy model for AdS/CFT\, we study the entanglement entropy of closed st
rings in the topological A model\, which enjoys a gauge-string duality.
We define a notion of generalized entropy for closed strings on the resolv
ed conifold using the replica trick. As in AdS/CFT\, we find this is dua
l to (defect) entanglement entropy in the dual Chern Simons gauge theory.
Our main result is a bulk microstate interpretation of the generalized e
ntropy for closed strings as the entanglement entropy of open strings endi
ng on ``entanglement branes" . These branes are interpreted as entangl
ement edge modes\, which transform under a quantum group symmetry. We rel
ate these entanglement branes to the D branes of the A model topological s
tring.\n
LOCATION:https://researchseminars.org/talk/nhetc/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sunil Mukhi (IISER Pune)
DTSTART;VALUE=DATE-TIME:20221208T190000Z
DTEND;VALUE=DATE-TIME:20221208T200000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/59
DESCRIPTION:Title: C
lassification of Unitary RCFTs with Two Primaries and c < 25\nby Sunil
Mukhi (IISER Pune) as part of NHETC Seminar\n\n\nAbstract\nI will present
a classification of all unitary\, rational\nconformal field theories with
two primaries\, central charge c < 25\,\nand arbitrary Wronskian index.
(Work in collaboration with Brandon\nRayhaun\, arXiv: 2208.05486). These a
re shown to be either certain\nlevel-1 WZW models or cosets of meromorphic
theories by such models.\nBy leveraging the existing classification of m
eromorphic CFTs of\ncentral charge c ≤ 24\, all the relevant cosets are
enumerated and\ntheir characters computed. This leads to 123 theories\, mo
st of which\nare new. It will be emphasised that this is a classification
of RCFTs\nand not just consistent characters.This work makes use of early\
nresults in the classification of RCFT using modular linear\ndifferential
equations and cosets\, the relevant background will be\nreviewed.\n
LOCATION:https://researchseminars.org/talk/nhetc/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Petr Hořava (UC Berkeley)
DTSTART;VALUE=DATE-TIME:20221213T193000Z
DTEND;VALUE=DATE-TIME:20221213T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/60
DESCRIPTION:Title: T
opological Quantum Gravity of the Ricci Flow\nby Petr Hořava (UC Berk
eley) as part of NHETC Seminar\n\n\nAbstract\nUsing the techniques of coho
mological quantum field theories\, we construct a topological nonrelativis
tic quantum gravity\, designed around the mathematical theory of the Ricci
flow on Riemannian manifolds\, as used by Perelman in his proof of the Po
incare conjecture and Thurston's geometrization theorem. This quantum fie
ld theory brings together three\, previously not directly related areas:
Topological field theory of the cohomological type\, nonrelativistic quant
um gravity of the Lifshitz type\, and the mathematics of geometric flows o
n manifolds. We identify the precise theory whose path integral localizes
to the solutions of the Perelman's version of the Ricci flow equations\,
and identify various features of Perelman's construction in the physics la
nguage\, such as Perelman's entropy functional (which plays the role of ou
r superpotential)\, Perelman's dilaton field (which maps to the lapse func
tion of nonrelativistic gravity)\, and others. With this embedding of Per
elman's Ricci flow to topological quantum gravity\, many intriguing result
s about the structure of the flow accumulated on the mathematical side in
the past two decades can now be imported into the physical picture in the
path integral formulation of quantum gravity.\n
LOCATION:https://researchseminars.org/talk/nhetc/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ingo Runkel (Universität Hamburg)
DTSTART;VALUE=DATE-TIME:20221220T193000Z
DTEND;VALUE=DATE-TIME:20221220T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/61
DESCRIPTION:Title: T
opological symmetries and their gaugings in 2dCFT and 3dTFT\nby Ingo R
unkel (Universität Hamburg) as part of NHETC Seminar\n\n\nAbstract\nThe s
tudy of topological defects in quantum field theory as seen a wealth of ac
tivity recently leading to many interesting insights\, for example the exp
licit realization of non-invertible topological defects in higher dimensio
nal QFTs via the gauging of higher form symmetries\, or the description of
the higher algebraic structures inherent in these topological defects. \n
\nIn this talk\, I would like to focus on low-dimensional examples\, where
such defects and their properties have been investigated for some time al
ready. I would like to exhibit some of the properties of topological defec
ts in two-dimensional conformal field theory and in three-dimensional topo
logical field theory\, and show some of the structural insights into 2dCFT
and 3dTFT one can gain with the help of defects. In this way\, the well-u
nderstood low-dimensional case might serves as a source of ideas and as a
test-case for higher dimensional constructions.\n
LOCATION:https://researchseminars.org/talk/nhetc/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Tong (University of Cambridge)
DTSTART;VALUE=DATE-TIME:20230124T193000Z
DTEND;VALUE=DATE-TIME:20230124T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/62
DESCRIPTION:Title: A
Chern-Simons Theory for the North Atlantic Ocean\nby David Tong (Univ
ersity of Cambridge) as part of NHETC Seminar\n\n\nAbstract\nIn some ways
the ocean acts like a topological insulator. There are chiral edge modes\,
localised at the coast\, that go clockwise in the Northern hemisphere and
anti-clockwise in the Southern hemisphere. I’ll describe these properti
es and explain how they can be understood in terms of something more famil
iar to high energy physicists. I’ll show that the equations that govern
the long-time dynamics of the ocean can be recast as a Maxwell-Chern-Simon
s theory.\n
LOCATION:https://researchseminars.org/talk/nhetc/62/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nathan Seiberg (Institute for Advanced Study)
DTSTART;VALUE=DATE-TIME:20230131T193000Z
DTEND;VALUE=DATE-TIME:20230131T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/63
DESCRIPTION:Title: S
ymmetries and Anomalies in the Continuum and on the Lattice\nby Nathan
Seiberg (Institute for Advanced Study) as part of NHETC Seminar\n\n\nAbst
ract\nBased on joint work with Meng Cheng (arXiv:2211.12543)\, we will dis
cuss some aspects of global symmetries and their ‘t Hooft anomalies.\n\n
We will define a notion of an emanant global symmetry. It is not a symmetr
y of the UV theory\, but unlike emergent (accidental) symmetries\, it is n
ot violated by any relevant or irrelevant operators in the IR theory.\n\nW
e will present lattice models with anomalous internal symmetries and see h
ow the anomalies are diagnosed on the lattice using topological defects.\n
\nWe will also discuss lattice models with anomalous lattice translation a
nd relate them to an anomalous emanant symmetry in the IR theory. This wil
l connect our discussion to the well-known Lieb-Schultz-Mattis theorem and
to filling constraints like Luttinger theorem.\n
LOCATION:https://researchseminars.org/talk/nhetc/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Johanna Erdmenger (Julius Maximilian University Würzburg)
DTSTART;VALUE=DATE-TIME:20230425T183000Z
DTEND;VALUE=DATE-TIME:20230425T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/64
DESCRIPTION:Title: D
iscrete Holography\nby Johanna Erdmenger (Julius Maximilian University
Würzburg) as part of NHETC Seminar\n\n\nAbstract\nI will review recent p
rogress towards establishing a holographic duality for discrete spaces inv
olving a regular tiling of hyperbolic space. In particular\, I will presen
t a recent example where an aperiodic XXZ spin chain is obtained naturally
by extrapolating the bulk tiling to its boundary. The properties of this
model are studied using RG techniques\, which provide a tensor network con
struction for its ground state. We calculate and compare the entanglement
entropy both at the boundary and in the bulk. I will comment on the symmet
ries of the construction and on the next steps towards obtaining a full dy
namical duality of discrete systems. In particular\, this may be useful fo
r going beyond the large N limit on the gravity side.\n\n Based on arXiv
2205.05693\, 2205.05081 and 2212.11292.\n
LOCATION:https://researchseminars.org/talk/nhetc/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fiona Burnell (University of Minnesota)
DTSTART;VALUE=DATE-TIME:20230523T183000Z
DTEND;VALUE=DATE-TIME:20230523T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/65
DESCRIPTION:Title: A
bulk-boundary correspondence for non-invertible symmetries\nby Fiona
Burnell (University of Minnesota) as part of NHETC Seminar\n\n\nAbstract\n
The notion that symmetry in a d-dimensional QFT is naturally described by
placing this QFT at the boundary of a d+1 dimensional TQFT has been very p
owerful in understanding generalized symmetry actions\, particularly for n
on-invertible symmetries. I discuss a concrete family of models in 2 spa
tial dimensions\, which can be viewed on the one hand as Hamiltonian model
s describing bulk topological orders\, and on the other hand (when the bul
k is in its ground state) as bulk TQFT’s describing a symmetry action at
the boundary. I will describe how to add additional symmetry by “shadi
ng” and “completing” the bulk models. This leads to models which r
ealize interesting symmetries in an onsite manner. Specifically\, in the
bulk\, these shaded models realize symmetries that permute the anyons in t
he underlying TQFT. At the boundary\, these symmetries can take the form
of generalized Kramers-Wannier dualities in the boundary spin model. I w
ill illustrate how this works in a few simple examples.\n
LOCATION:https://researchseminars.org/talk/nhetc/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mihoko Nojiri (KEK Theory Center)
DTSTART;VALUE=DATE-TIME:20230202T173000Z
DTEND;VALUE=DATE-TIME:20230202T183000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/67
DESCRIPTION:Title: F
uture electron beam dump experiments\nby Mihoko Nojiri (KEK Theory Cen
ter) as part of NHETC Seminar\n\n\nAbstract\nA beam dump experiment can be
seamlessly added to the proposed International Linear Collider (ILC) prog
ram because the high-energy electron beam should be dumped after the colli
sion point. The ILC beam dump experiment will provide an excellent opportu
nity to search for new long-lived particles(LLP). An LPP couple to a photo
n\, such as axion-like particles\, can be searched there. Furthermore\, th
e photon and electron in EM shower hit nuclei and produce hadrons. As a mo
tivated physics case\, we study the projected sensitivity of heavy neutral
leptons at the ILC beam dump experiment. The study shows\,somewhat counte
r-intuitively\, that the reach would be significantly extended in mass and
coupling\, even compared with the other proposed searches. I also intro
duce proposed ALP studies using KEK linac\; currently\, test beam studies
are starting.\n
LOCATION:https://researchseminars.org/talk/nhetc/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Malte Buschmann (Princeton University)
DTSTART;VALUE=DATE-TIME:20230207T193000Z
DTEND;VALUE=DATE-TIME:20230207T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/68
DESCRIPTION:Title: T
he post-inflationary axion\nby Malte Buschmann (Princeton University)
as part of NHETC Seminar\n\n\nAbstract\nThe axion is a hypothetical partic
le that solves the strong CP problem of quantum chromodynamics (QCD) while
simultaneously being an excellent dark matter candidate. If the axion is
generated after inflation\, many unique objects arise from the theory\, fr
om axion strings and domain walls to oscillons\, miniclusters\, and axion
stars. The result is many potentially observable signatures\, whether in t
he CMB\, the gravitational wave background or in neutron star data. More i
mportantly\, this scenario is entirely deterministic\, allowing precise pr
edictions through numerical simulations. In this talk\, I will go through
the cosmological history of such a post-inflationary axion to put the vari
ous phenomena into context and highlight the remaining open questions.\n
LOCATION:https://researchseminars.org/talk/nhetc/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edward Witten (Institute for Advanced Study)
DTSTART;VALUE=DATE-TIME:20230221T193000Z
DTEND;VALUE=DATE-TIME:20230221T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/69
DESCRIPTION:Title: T
he Timelike Tube Theorem\nby Edward Witten (Institute for Advanced Stu
dy) as part of NHETC Seminar\n\n\nAbstract\nI will explain the ideas invol
ved in the timelike tube theorem\, which says that the algebra of quantum
fields along the worldline of an observer is the same as (roughly) the a
lgebra of quantum fields in a spacetime region that is causally accessible
to the observer. The earliest version was proved by Borchers and Araki in
the 1960's.\n
LOCATION:https://researchseminars.org/talk/nhetc/69/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Manuel Szewc (University of Cincinnati)
DTSTART;VALUE=DATE-TIME:20230307T193000Z
DTEND;VALUE=DATE-TIME:20230307T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/71
DESCRIPTION:Title: N
ull Hypothesis Test for Anomaly Detection\nby Manuel Szewc (University
of Cincinnati) as part of NHETC Seminar\n\n\nAbstract\nIn this talk we pr
esent a hypothesis test designed to exclude the background-only hypothesis
for Anomaly detection searchs. Extending Classification Without Labels\,
we show that by testing for statistical independence of the two discrimina
ting dataset regions\, we are able exclude the background-only hypothesis
without relying on fixed anomaly score cuts or extrapolations of backgroun
d estimates between regions. The method relies on the assumption of condit
ional independence of anomaly score features and dataset regions\, which c
an be ensured using existing decorrelation techniques. As a benchmark exam
ple\, we consider the LHC Olympics dataset where we show that mutual infor
mation represents a suitable test for statistical independence and our met
hod exhibits excellent and robust performance at different signal fraction
s even in presence of realistic feature correlations.\n
LOCATION:https://researchseminars.org/talk/nhetc/71/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gleb Kotousov (Leibniz University Hannover)
DTSTART;VALUE=DATE-TIME:20230309T190000Z
DTEND;VALUE=DATE-TIME:20230309T200000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/72
DESCRIPTION:Title: 2
D black hole sigma models from an integrable spin chain\nby Gleb Kotou
sov (Leibniz University Hannover) as part of NHETC Seminar\n\n\nAbstract\n
The staggered six-vertex model is a 1D critical integrable spin chain that
exhibits a variety of interesting universal behaviour. This includes a re
gime where the spectrum of critical exponents contains a continuous compon
ent and matches that of the Euclidean version of the 2D black hole non-lin
ear sigma model. In this talk the relation between the scaling limit of th
e vertex model and the Euclidean/Lorentzian black hole sigma models is dis
cussed. Some new results on the density of states of the continuous spectr
um for the Euclidean black hole CFT are presented\, which were obtained vi
a an analysis of the lattice system. The talk is largely based on the work
2010.10603.\n
LOCATION:https://researchseminars.org/talk/nhetc/72/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kevin Croker (University of Hawaii)
DTSTART;VALUE=DATE-TIME:20230314T183000Z
DTEND;VALUE=DATE-TIME:20230314T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/73
DESCRIPTION:by Kevin Croker (University of Hawaii) as part of NHETC Semina
r\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/73/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Dunsky (NYU)
DTSTART;VALUE=DATE-TIME:20230321T183000Z
DTEND;VALUE=DATE-TIME:20230321T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/74
DESCRIPTION:Title: A
Heavy QCD Axion and the Mirror World\nby David Dunsky (NYU) as part o
f NHETC Seminar\n\n\nAbstract\nIn this talk\, I will discuss the mirror wo
rld with dark matter arising from the thermal freeze-out of the lightest\,
stable mirror particle -- the mirror electron. The dark matter abundance
is achieved for mirror electrons of mass 225 GeV\, fixing the mirror elect
roweak scale near 10^8 GeV. This highly predictive scenario is realized by
an axion that acts as a portal between the two sectors through its coupli
ng to the QCD and mirror QCD sectors. The axion is more massive than the s
tandard QCD axion due to additional contributions from mirror strong dynam
ics. Still\, the strong CP problem is solved by this "heavy" axion due to
the alignment of the QCD and mirror QCD potentials. Mirror entropy is tran
sferred into the Standard Model sector via the axion portal\, which allevi
ates overproduction of dark radiation from mirror glueball decays. I will
discuss four signals from this model: (1) primordial gravitational waves f
rom the first-order mirror QCD phase transition occurring at a temperature
near 35 GeV\, (2) effects on large-scale structure from dark matter self-
interactions from mirror QED\, (3) dark radiation affecting the cosmic mic
rowave background\, and (4) the rare kaon decay\, (kaon -> pion +axion). T
he first two signals do not depend on any fundamental free parameters of t
he theory while the latter two depend on a single free parameter\, the axi
on decay constant.\n
LOCATION:https://researchseminars.org/talk/nhetc/74/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Annika Peter (Harvard)
DTSTART;VALUE=DATE-TIME:20230404T183000Z
DTEND;VALUE=DATE-TIME:20230404T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/75
DESCRIPTION:by Annika Peter (Harvard) as part of NHETC Seminar\n\nAbstract
: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/75/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seth Koren (Chicago)
DTSTART;VALUE=DATE-TIME:20230502T183000Z
DTEND;VALUE=DATE-TIME:20230502T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/76
DESCRIPTION:Title: P
utting Generalized Symmetries to Work for Particle Physics\nby Seth Ko
ren (Chicago) as part of NHETC Seminar\n\n\nAbstract\nOver the past decade
\, field theorists have developed a novel framework for thinking about glo
bal symmetries which has enormously generalized our understanding thereof.
Quite recently\, my collaborators and I have established positively that
past being a useful formal tool\, such generalized symmetries are indeed p
resent in models that we care about as particle physicists---and furthermo
re understanding them can lead to new insights into these models. As a fir
st example\, the Standard Model itself has a 'higher-group' symmetry inter
twining flavor and hypercharge\, and I will discuss how this symmetry cont
rols the structure of unification. Going Beyond\, I will show that the ide
ntification of a 'non-invertible' symmetry of Z' models of L_µ - L_τ rev
eals the existence of simple UV completions thereof where the scale of neu
trino masses is exponentially suppressed from that of charged leptons.\n
LOCATION:https://researchseminars.org/talk/nhetc/76/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mariel Pettee (Lawrence Berkeley National Laboratory / Flatiron In
stitute Center for Computational Astrophysics)
DTSTART;VALUE=DATE-TIME:20230511T163000Z
DTEND;VALUE=DATE-TIME:20230511T183000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/77
DESCRIPTION:Title: W
eakly-Supervised Anomaly Detection in the Milky Way\nby Mariel Pettee
(Lawrence Berkeley National Laboratory / Flatiron Institute Center for Com
putational Astrophysics) as part of NHETC Seminar\n\n\nAbstract\nClassific
ation Without Labels (CWoLa) is a weakly-supervised anomaly detection tech
nique that leverages neural networks to identify cold stellar streams with
in the more than one billion Milky Way stars observed by the Gaia satellit
e. The CWoLa methodology operates without the use of labeled streams or kn
owledge of astrophysical principles. Instead\, it uses a classifier to dis
tinguish between mixed samples for which the proportions of signal and bac
kground samples are unknown. This computationally lightweight strategy is
able to detect both simulated streams and the known stream GD-1 in data. O
riginally designed for high-energy collider physics\, this technique may h
ave broad applicability within astrophysics as well as other domains inter
ested in identifying localized anomalies.\n
LOCATION:https://researchseminars.org/talk/nhetc/77/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan Heckman (University of Pennsylvania)
DTSTART;VALUE=DATE-TIME:20230228T193000Z
DTEND;VALUE=DATE-TIME:20230228T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/78
DESCRIPTION:Title: I
IB Determined\nby Jonathan Heckman (University of Pennsylvania) as par
t of NHETC Seminar\n\n\nAbstract\nWe use the Swampland Cobordism Conjectur
e recently proposed by McNamara and Vafa to study the spectrum of objects
in type IIB string theory. A famous feature of type IIB string theory (as
well as many quantum systems) is that it enjoys a non-abelian duality grou
p. By computing the relevant cobordism groups\, we show that the cobordism
conjecture successfully reconstructs many known supersymmetric objects\,
and also predicts the existence of a new non-supersymmetric "reflection 7-
brane\," the properties of which we describe. Based on joint work with Deb
ray\, Dierigl\, Montero and Torres.\n
LOCATION:https://researchseminars.org/talk/nhetc/78/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lina Necib (MIT)
DTSTART;VALUE=DATE-TIME:20230905T183000Z
DTEND;VALUE=DATE-TIME:20230905T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/79
DESCRIPTION:Title: (
Machine) Learning of Dark Matter\nby Lina Necib (MIT) as part of NHETC
Seminar\n\n\nAbstract\nIn this talk\, I explore the impact of stellar kin
ematics on understanding the particle nature of Dark Matter\, overviewing
the correlations between stellar and Dark Matter phase space distributions
in three separate locations: the solar neighborhood\, the Galactic center
\, and dwarf galaxies. I will focus on the use of machine learning techniq
ues applied to data from the Gaia mission to disentangle the local kinemat
ics substructures\, and the use of simulations to study the correlations b
etween stars and Dark Matter. I will end by relating these empirical measu
rements to Dark Matter detection experiments.\n
LOCATION:https://researchseminars.org/talk/nhetc/79/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Katherine Fraser (Harvard)
DTSTART;VALUE=DATE-TIME:20230418T183000Z
DTEND;VALUE=DATE-TIME:20230418T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/80
DESCRIPTION:by Katherine Fraser (Harvard) as part of NHETC Seminar\n\nAbst
ract: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/80/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stefano Negro (NYU)
DTSTART;VALUE=DATE-TIME:20230328T183000Z
DTEND;VALUE=DATE-TIME:20230328T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/81
DESCRIPTION:Title: T
he relevance of being irrelevant\nby Stefano Negro (NYU) as part of NH
ETC Seminar\n\n\nAbstract\nIn the last few years\, 2-dimensional Quantum F
ield Theories deformed by irrelevant operators have been receiving a stead
ily growing amount of attention from the Theoretical Physics community. Th
e main reason for this interest lies in the unexpected amount of control t
hat it is possible to exert on the high-energy properties of a vast family
of these deformations. These\, often referred to as “solvable irrelevan
t deformations”\, in spite of being by standard arguments non-renormalis
able\, allow us to follow the irrelevant flow all the way to the UV and to
obtain exact results on the high-energy physics. The latter are remarkabl
e: the finite-size density of states grows exponentially at high energies\
, in a Hagedorn fashion reminiscent of String Theories. These deformed the
ories are not compatible with Wilson’s paradigm of local QFTs and cannot
be considered conventional UV-complete theories. However\, thanks to thei
r robust features\, they represent a sensible extension of the Wilsonian n
otion of a local QFT.\n\nI will recall the main features of the TTbar defo
rmations\, the poster child of solvable irrelevant deformations\, in an in
troductory manner. If time permits I will then describe the more recent de
velopments for a vast class of irrelevant deformations of 2D Integrable QF
Ts\, paying particular attention to their interpretation as factorised sca
ttering theories. This perspective reveals the importance of these theorie
s in the task undertaken by the Bootstrap community of mapping out the spa
ce of consistent scattering matrices.\n
LOCATION:https://researchseminars.org/talk/nhetc/81/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Banks (Rutgers)
DTSTART;VALUE=DATE-TIME:20230323T183000Z
DTEND;VALUE=DATE-TIME:20230323T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/82
DESCRIPTION:Title: T
he Density Matrix of a Causal Diamond\nby Thomas Banks (Rutgers) as pa
rt of NHETC Seminar\n\n\nAbstract\nI will review and reinterpret a number
of papers from the 1990s\, which indicate that the operator algebra of a c
ausal diamond in models of quantum gravity is finite dimensional and that
the modular Hamiltonian of the "empty diamond" state has an expectation va
lue and fluctuations determined by geometrical properties of the diamond.
These universal formulae depend on a view of Einstein's equations as the
hydrodynamic equations of the area law for diamond entropy\, which means t
hat they are valid beyond any "semi-classical" approximation. A model of
quantum gravity consists of finding a quantum system whose hydrodynamics i
s consistent with a given solution of Einstein's equations. I will quickl
y review many papers and attendees are encouraged to read them before the
talk. (List will follow). Among the many implications of these papers is
that quantum field theory cannot account for most of the entropy in a cau
sal diamond\, and that the cosmological constant should not be thought of
as an energy density. \n\nReferences:\n\n 1. A. G. Cohen\, D. B. Kaplan
and A. E. Nelson\, Phys. Rev. Lett. 82\, 4971-4974 (1999)doi:10.1103/Phys
RevLett.82.4971 [arXiv:hep-th/9803132 [hep-th]].\n\n 2. T. Banks and P.
Draper\, Phys. Rev. D 101\, no.12\, 126010 (2020) doi:10.1103/PhysRevD.10
1.126010[arXiv:1911.05778 [hep-th]].\n\n 3. N. Blinov and P. Draper\, P
hys. Rev. D 104\, no.7\, 076024 (2021) doi:10.1103/PhysRevD.104.076024[arX
iv:2107.03530 [hep-ph]].\n\n 4. R. D. Sorkin\, [arXiv:1402.3589 [gr-qc]
].\n\n 5. M. Srednicki\, Phys. Rev. Lett. 71\, 666-669 (1993) doi:10.11
03/PhysRevLett.71.666[arXiv:hep-th/9303048 [hep-th]].\n\n 6. C. G. Call
an\, Jr. and F. Wilczek\, Phys. Lett. B 333\, 55-61 (1994) doi:10.1016/037
0-2693(94)91007-3 [arXiv:hep-th/9401072 [hep-th]].\n\n 7. L. Susskind a
nd J. Uglum\, Phys. Rev. D 50\, 2700-2711 (1994) doi:10.1103/PhysRevD.50.2
700[arXiv:hep-th/9401070 [hep-th]].\n\n 8. T. Jacobson\, [arXiv:gr-qc/9
404039 [gr-qc]].\n\n 9. T. Jacobson\, Phys. Rev. Lett. 75\, 1260-1263 (
1995) doi:10.1103/PhysRevLett.75.1260[arXiv:gr-qc/9504004 [gr-qc]].\n\n
10. W. Fischler and L. Susskind\, [arXiv:hep-th/9806039 [hep-th]].\n\n
11. R. Bousso\, Class. Quant. Grav. 17\, 997-1005 (2000) doi:10.1088/0264
-9381/17/5/309[arXiv:hep-th/9911002 [hep-th]]. ETC.\n\n 12. H. L. Verli
nde and E. P. Verlinde\, Nucl. Phys. B 371\, 246-268 (1992) doi:10.1016/05
50-3213(92)90236-5 [arXiv:hep-th/9110017 [hep-th]].\n\n 13. S. Carlip\,
Phys. Rev. Lett. 82\, 2828-2831 (1999) doi:10.1103/PhysRevLett.82.2828[ar
Xiv:hep-th/9812013 [hep-th]]. ETC.\n\n 14. S. N. Solodukhin\, Phys. Let
t. B 454\, 213-222 (1999) doi:10.1016/S0370-2693(99)00398-6[arXiv:hep-th/9
812056 [hep-th]]. \n\n 15. T. Banks and K. M. Zurek\, Phys. Rev. D 104
\, no.12\, 126026 (2021) doi:10.1103/PhysRevD.104.126026[arXiv:2108.04806
[hep-th]].\n
LOCATION:https://researchseminars.org/talk/nhetc/82/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Banks (Rutgers)
DTSTART;VALUE=DATE-TIME:20230330T183000Z
DTEND;VALUE=DATE-TIME:20230330T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/83
DESCRIPTION:Title: T
he Density Matrix of a Causal Diamond\nby Thomas Banks (Rutgers) as pa
rt of NHETC Seminar\n\n\nAbstract\nI will review and reinterpret a number
of papers from the 1990s\, which indicate that the operator algebra of a c
ausal diamond in models of quantum gravity is finite dimensional and that
the modular Hamiltonian of the "empty diamond" state has an expectation va
lue and fluctuations determined by geometrical properties of the diamond.
These universal formulae depend on a view of Einstein's equations as the
hydrodynamic equations of the area law for diamond entropy\, which means t
hat they are valid beyond any "semi-classical" approximation. A model of
quantum gravity consists of finding a quantum system whose hydrodynamics i
s consistent with a given solution of Einstein's equations. I will quickl
y review many papers and attendees are encouraged to read them before the
talk. (List will follow). Among the many implications of these papers is
that quantum field theory cannot account for most of the entropy in a cau
sal diamond\, and that the cosmological constant should not be thought of
as an energy density. \n\nReferences:\n\n 1. A. G. Cohen\, D. B. Kaplan
and A. E. Nelson\, Phys. Rev. Lett. 82\, 4971-4974 (1999)doi:10.1103/Phys
RevLett.82.4971 [arXiv:hep-th/9803132 [hep-th]].\n\n 2. T. Banks and P.
Draper\, Phys. Rev. D 101\, no.12\, 126010 (2020) doi:10.1103/PhysRevD.10
1.126010[arXiv:1911.05778 [hep-th]].\n\n 3. N. Blinov and P. Draper\, P
hys. Rev. D 104\, no.7\, 076024 (2021) doi:10.1103/PhysRevD.104.076024[arX
iv:2107.03530 [hep-ph]].\n\n 4. R. D. Sorkin\, [arXiv:1402.3589 [gr-qc]
].\n\n 5. M. Srednicki\, Phys. Rev. Lett. 71\, 666-669 (1993) doi:10.11
03/PhysRevLett.71.666[arXiv:hep-th/9303048 [hep-th]].\n\n 6. C. G. Call
an\, Jr. and F. Wilczek\, Phys. Lett. B 333\, 55-61 (1994) doi:10.1016/037
0-2693(94)91007-3 [arXiv:hep-th/9401072 [hep-th]].\n\n 7. L. Susskind a
nd J. Uglum\, Phys. Rev. D 50\, 2700-2711 (1994) doi:10.1103/PhysRevD.50.2
700[arXiv:hep-th/9401070 [hep-th]].\n\n 8. T. Jacobson\, [arXiv:gr-qc/9
404039 [gr-qc]].\n\n 9. T. Jacobson\, Phys. Rev. Lett. 75\, 1260-1263 (
1995) doi:10.1103/PhysRevLett.75.1260[arXiv:gr-qc/9504004 [gr-qc]].\n\n
10. W. Fischler and L. Susskind\, [arXiv:hep-th/9806039 [hep-th]].\n\n
11. R. Bousso\, Class. Quant. Grav. 17\, 997-1005 (2000) doi:10.1088/0264
-9381/17/5/309[arXiv:hep-th/9911002 [hep-th]]. ETC.\n\n 12. H. L. Verli
nde and E. P. Verlinde\, Nucl. Phys. B 371\, 246-268 (1992) doi:10.1016/05
50-3213(92)90236-5 [arXiv:hep-th/9110017 [hep-th]].\n\n 13. S. Carlip\,
Phys. Rev. Lett. 82\, 2828-2831 (1999) doi:10.1103/PhysRevLett.82.2828[ar
Xiv:hep-th/9812013 [hep-th]]. ETC.\n\n 14. S. N. Solodukhin\, Phys. Let
t. B 454\, 213-222 (1999) doi:10.1016/S0370-2693(99)00398-6[arXiv:hep-th/9
812056 [hep-th]]. \n\n 15. T. Banks and K. M. Zurek\, Phys. Rev. D 104
\, no.12\, 126026 (2021) doi:10.1103/PhysRevD.104.126026[arXiv:2108.04806
[hep-th]].\n
LOCATION:https://researchseminars.org/talk/nhetc/83/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gabriel Wong (Harvard CMSA)
DTSTART;VALUE=DATE-TIME:20230504T180000Z
DTEND;VALUE=DATE-TIME:20230504T190000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/84
DESCRIPTION:Title: G
eneralized entropy in topological string theory\nby Gabriel Wong (Harv
ard CMSA) as part of NHETC Seminar\n\n\nAbstract\nThe holographic entangle
ment entropy formula identifies the generalized entropy of the bulk AdS sp
acetime with the entanglement entropy of the boundary CFT. However the bul
k microstate interpretation of the generalized entropy remains poorly unde
rstood. Progress along this direction requires a definition of Hilbert sp
ace factorization and entanglement entropy in the bulk closed string theor
y. As a toy model for AdS/CFT\, we study the entanglement entropy of clos
ed strings in the topological A model\, which enjoys a gauge-string dualit
y. We define a notion of generalized entropy for closed strings on the re
solved conifold using the replica trick. As in AdS/CFT\, we find this is
dual to (defect) entanglement entropy in the dual Chern Simons gauge theo
ry. Our main result is a bulk microstate interpretation of the generaliz
ed entropy for closed strings as the entanglement entropy of open strings
ending on ``entanglement branes" . These branes are interpreted as entangl
ement edge modes\, which transform under a quantum group symmetry. We rel
ate these entanglement branes to the Dbranes of the A model topological st
ring.\n
LOCATION:https://researchseminars.org/talk/nhetc/84/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Banks (Rutgers)
DTSTART;VALUE=DATE-TIME:20230427T183000Z
DTEND;VALUE=DATE-TIME:20230427T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/85
DESCRIPTION:Title: T
he Density Matrix Of A Causal Diamond\nby Thomas Banks (Rutgers) as pa
rt of NHETC Seminar\n\n\nAbstract\nI will review and reinterpret a number
of papers from the 1990s\, which indicate that the operator algebra of a c
ausal diamond in models of quantum gravity is finite dimensional and that
the modular Hamiltonian of the "empty diamond" state has an expectation va
lue and fluctuations determined by geometrical properties of the diamond.
These universal formulae depend on a view of Einstein's equations as the
hydrodynamic equations of the area law for diamond entropy\, which means t
hat they are valid beyond any "semi-classical" approximation. A model of
quantum gravity consists of finding a quantum system whose hydrodynamics i
s consistent with a given solution of Einstein's equations. I will quickl
y review many papers and attendees are encouraged to read them before the
talk. (List will follow). Among the many implications of these papers is
that quantum field theory cannot account for most of the entropy in a cau
sal diamond\, and that the cosmological constant should not be thought of
as an energy density. \n\nReferences:\n\n 1. A. G. Cohen\, D. B. Kaplan
and A. E. Nelson\, Phys. Rev. Lett. 82\, 4971-4974 (1999)doi:10.1103/Phys
RevLett.82.4971 [arXiv:hep-th/9803132 [hep-th]].\n\n 2. T. Banks and P.
Draper\, Phys. Rev. D 101\, no.12\, 126010 (2020) doi:10.1103/PhysRevD.10
1.126010[arXiv:1911.05778 [hep-th]].\n\n 3. N. Blinov and P. Draper\, P
hys. Rev. D 104\, no.7\, 076024 (2021) doi:10.1103/PhysRevD.104.076024[arX
iv:2107.03530 [hep-ph]].\n\n 4. R. D. Sorkin\, [arXiv:1402.3589 [gr-qc]
].\n\n 5. M. Srednicki\, Phys. Rev. Lett. 71\, 666-669 (1993) doi:10.11
03/PhysRevLett.71.666[arXiv:hep-th/9303048 [hep-th]].\n\n 6. C. G. Call
an\, Jr. and F. Wilczek\, Phys. Lett. B 333\, 55-61 (1994) doi:10.1016/037
0-2693(94)91007-3 [arXiv:hep-th/9401072 [hep-th]].\n\n 7. L. Susskind a
nd J. Uglum\, Phys. Rev. D 50\, 2700-2711 (1994) doi:10.1103/PhysRevD.50.2
700[arXiv:hep-th/9401070 [hep-th]].\n\n 8. T. Jacobson\, [arXiv:gr-qc/9
404039 [gr-qc]].\n\n 9. T. Jacobson\, Phys. Rev. Lett. 75\, 1260-1263 (
1995) doi:10.1103/PhysRevLett.75.1260[arXiv:gr-qc/9504004 [gr-qc]].\n\n
10. W. Fischler and L. Susskind\, [arXiv:hep-th/9806039 [hep-th]].\n\n
11. R. Bousso\, Class. Quant. Grav. 17\, 997-1005 (2000) doi:10.1088/0264
-9381/17/5/309[arXiv:hep-th/9911002 [hep-th]]. ETC.\n\n 12. H. L. Verli
nde and E. P. Verlinde\, Nucl. Phys. B 371\, 246-268 (1992) doi:10.1016/05
50-3213(92)90236-5 [arXiv:hep-th/9110017 [hep-th]].\n\n 13. S. Carlip\,
Phys. Rev. Lett. 82\, 2828-2831 (1999) doi:10.1103/PhysRevLett.82.2828[ar
Xiv:hep-th/9812013 [hep-th]]. ETC.\n\n 14. S. N. Solodukhin\, Phys. Let
t. B 454\, 213-222 (1999) doi:10.1016/S0370-2693(99)00398-6[arXiv:hep-th/9
812056 [hep-th]]. \n\n 15. T. Banks and K. M. Zurek\, Phys. Rev. D 104
\, no.12\, 126026 (2021) doi:10.1103/PhysRevD.104.126026[arXiv:2108.04806
[hep-th]].\n
LOCATION:https://researchseminars.org/talk/nhetc/85/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Banks (Rutgers)
DTSTART;VALUE=DATE-TIME:20230511T183000Z
DTEND;VALUE=DATE-TIME:20230511T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/86
DESCRIPTION:Title: T
he Density Matrix Of A Causal Diamond\nby Thomas Banks (Rutgers) as pa
rt of NHETC Seminar\n\n\nAbstract\nI will review and reinterpret a number
of papers from the 1990s\, which indicate that the operator algebra of a c
ausal diamond in models of quantum gravity is finite dimensional and that
the modular Hamiltonian of the "empty diamond" state has an expectation va
lue and fluctuations determined by geometrical properties of the diamond.
These universal formulae depend on a view of Einstein's equations as the
hydrodynamic equations of the area law for diamond entropy\, which means t
hat they are valid beyond any "semi-classical" approximation. A model of
quantum gravity consists of finding a quantum system whose hydrodynamics i
s consistent with a given solution of Einstein's equations. I will quickl
y review many papers and attendees are encouraged to read them before the
talk. (List will follow). Among the many implications of these papers is
that quantum field theory cannot account for most of the entropy in a cau
sal diamond\, and that the cosmological constant should not be thought of
as an energy density. \n\nReferences:\n\n 1. A. G. Cohen\, D. B. Kaplan
and A. E. Nelson\, Phys. Rev. Lett. 82\, 4971-4974 (1999)doi:10.1103/Phys
RevLett.82.4971 [arXiv:hep-th/9803132 [hep-th]].\n\n 2. T. Banks and P.
Draper\, Phys. Rev. D 101\, no.12\, 126010 (2020) doi:10.1103/PhysRevD.10
1.126010[arXiv:1911.05778 [hep-th]].\n\n 3. N. Blinov and P. Draper\, P
hys. Rev. D 104\, no.7\, 076024 (2021) doi:10.1103/PhysRevD.104.076024[arX
iv:2107.03530 [hep-ph]].\n\n 4. R. D. Sorkin\, [arXiv:1402.3589 [gr-qc]
].\n\n 5. M. Srednicki\, Phys. Rev. Lett. 71\, 666-669 (1993) doi:10.11
03/PhysRevLett.71.666[arXiv:hep-th/9303048 [hep-th]].\n\n 6. C. G. Call
an\, Jr. and F. Wilczek\, Phys. Lett. B 333\, 55-61 (1994) doi:10.1016/037
0-2693(94)91007-3 [arXiv:hep-th/9401072 [hep-th]].\n\n 7. L. Susskind a
nd J. Uglum\, Phys. Rev. D 50\, 2700-2711 (1994) doi:10.1103/PhysRevD.50.2
700[arXiv:hep-th/9401070 [hep-th]].\n\n 8. T. Jacobson\, [arXiv:gr-qc/9
404039 [gr-qc]].\n\n 9. T. Jacobson\, Phys. Rev. Lett. 75\, 1260-1263 (
1995) doi:10.1103/PhysRevLett.75.1260[arXiv:gr-qc/9504004 [gr-qc]].\n\n
10. W. Fischler and L. Susskind\, [arXiv:hep-th/9806039 [hep-th]].\n\n
11. R. Bousso\, Class. Quant. Grav. 17\, 997-1005 (2000) doi:10.1088/0264
-9381/17/5/309[arXiv:hep-th/9911002 [hep-th]]. ETC.\n\n 12. H. L. Verli
nde and E. P. Verlinde\, Nucl. Phys. B 371\, 246-268 (1992) doi:10.1016/05
50-3213(92)90236-5 [arXiv:hep-th/9110017 [hep-th]].\n\n 13. S. Carlip\,
Phys. Rev. Lett. 82\, 2828-2831 (1999) doi:10.1103/PhysRevLett.82.2828[ar
Xiv:hep-th/9812013 [hep-th]]. ETC.\n\n 14. S. N. Solodukhin\, Phys. Let
t. B 454\, 213-222 (1999) doi:10.1016/S0370-2693(99)00398-6[arXiv:hep-th/9
812056 [hep-th]]. \n\n 15. T. Banks and K. M. Zurek\, Phys. Rev. D 104
\, no.12\, 126026 (2021) doi:10.1103/PhysRevD.104.126026[arXiv:2108.04806
[hep-th]].\n
LOCATION:https://researchseminars.org/talk/nhetc/86/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Veronica Pasquarella (University of Cambridge)
DTSTART;VALUE=DATE-TIME:20230912T183000Z
DTEND;VALUE=DATE-TIME:20230912T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/87
DESCRIPTION:Title: C
ategorical Symmetries and Fiber Functors from Multiple Condensing Homomorp
hisms from 6D N=(2\,0) SCFTs\nby Veronica Pasquarella (University of C
ambridge) as part of NHETC Seminar\n\n\nAbstract\nhis talk is structured i
nto two parts\, each one exploiting the symmetry topological field theory
/topological order correspondence (SymTFT/TO). On the one hand\, this enab
les to further the understanding of the categorical structure arising from
dimensional reduction of 6D N = (2\, 0) SCFTs\, identifying a criterion t
o distinguish between intrinsic and non-intrinsic non-invertible symmetrie
s in terms of the quantum dimension of condensable algebras. On the other\
, it addresses the issue of determining the fiber functor and Drinfeld cen
ter for a system of joined absolute theories separated by non invertible d
efects. Concluding remarks include the usefulness of these insights for fu
rthering the understanding of the interplay between gauge theory\, repres
entation theory and 3D mirror symmetry.\n
LOCATION:https://researchseminars.org/talk/nhetc/87/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hao Lan-Xu (Stony Brook University)
DTSTART;VALUE=DATE-TIME:20230921T183000Z
DTEND;VALUE=DATE-TIME:20230921T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/88
DESCRIPTION:Title: A
nalyticity properties of 2d Ising Field Theories\nby Hao Lan-Xu (Stony
Brook University) as part of NHETC Seminar\n\n\nAbstract\nIn this talk\,
I will discuss the analyticity properties of 2d Ising field theories (IFTs
). I will start with a short introduction to 2d Ising field theory\, which
is the continuous limit of the 2d Ising model on square lattice. Then the
different spectrum scenarios for high-T and low-T domains will be introdu
ced. Generally speaking\, an IFT which sits not at the critical temperatur
e and has a non-vanishing external field is neither solvable nor integrabl
e. However\, it's possible to look into the analytical properties of vario
us quantities in the theory space\, then further non-perturbative informat
ion can be extracted. I will focus on the analyticity properties for mass
of the first excitation\, and discuss its critical behaviours and dispersi
on relation in both ordered and disordered phase. Finally\, if time allowe
d\, I will switch the topic and discuss the analyticity properties of the
analytical structure of S-matrices\, and show various related interesting
phenomenons together with unsolved questions.\n\nReferences:\n[1] Ising fi
eld theory in a magnetic field: Analytic properties of the free energy\, P
. Fonseca and A. Zamolodchikov\, hep-th/0112167 [hep-th].\n[2] Ising Spect
roscopy II: Particles and poles at T > Tc\, A. Zamolodchikov\, 1310.4821 [
hep-th].\n[3] 2D Ising Field Theory in a magnetic field: the Yang-Lee sing
ularity\, H. Xu and A. Zamolodchikov\, 2203.11262 [hep-th].\n[4] On the S-
matrix of Ising field theory in two dimensions\, B. Gabai and X. Yin\, 190
5.00710 [hep-th]\n[5] Ising Field Theory in a Magnetic Field: Extended ana
lyticity properties of M1\, H. Xu\, in preparation.\n
LOCATION:https://researchseminars.org/talk/nhetc/88/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michael Winer (University of Maryland)
DTSTART;VALUE=DATE-TIME:20230926T183000Z
DTEND;VALUE=DATE-TIME:20230926T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/89
DESCRIPTION:Title: T
he Spectral Form Factor: From Hydrodynamics to the Riemann Zeta Function\nby Michael Winer (University of Maryland) as part of NHETC Seminar\n\n
Abstract: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/89/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kathryn Zurek (Caltech)
DTSTART;VALUE=DATE-TIME:20231010T183000Z
DTEND;VALUE=DATE-TIME:20231010T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/90
DESCRIPTION:by Kathryn Zurek (Caltech) as part of NHETC Seminar\n\nAbstrac
t: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/90/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dan Freed (Harvard)
DTSTART;VALUE=DATE-TIME:20231017T183000Z
DTEND;VALUE=DATE-TIME:20231017T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/91
DESCRIPTION:Title: W
hat is an anomaly?\nby Dan Freed (Harvard) as part of NHETC Seminar\n\
n\nAbstract\nAnomalies in quantum field theory have been the subject of at
tention for decades. In this talk I will dispel some myths: anomalies are
tied to symmetry\, anomalies are tied to fermionic fields\, etc. Then I
will explain how anomalies--expressed as invertible field theories--are th
e manifestation of the projectivity of quantum field theory. My point of
view is summarized by a slogan:\n\n Quantum theory is projectiv
e. Quantization is linear.\n
LOCATION:https://researchseminars.org/talk/nhetc/91/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eliezer Rabinovici (CERN)
DTSTART;VALUE=DATE-TIME:20231024T183000Z
DTEND;VALUE=DATE-TIME:20231024T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/92
DESCRIPTION:Title: S
ome Aspects of Krylov Complexity\nby Eliezer Rabinovici (CERN) as part
of NHETC Seminar\n\n\nAbstract\nA review of the concept of Krylov Complex
ity (K-Complexity) will be presented. One feature of K-Complexity is that
its definition does not involve a tolerance parameter. I will describe som
e general properties of K-Complexity\, its behavior when interpolating amo
ng various types of systems: free\, strongly integrable and chaotic ones.
Finally for a certain low dimensional system in a certain state I will des
cribe an explicit derivation of the geometric bulk dual of K complexity.\n
LOCATION:https://researchseminars.org/talk/nhetc/92/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brian Swingle (Brandeis)
DTSTART;VALUE=DATE-TIME:20231114T193000Z
DTEND;VALUE=DATE-TIME:20231114T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/93
DESCRIPTION:by Brian Swingle (Brandeis) as part of NHETC Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/93/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Akshay Ghalsasi (University of Pittsburgh)
DTSTART;VALUE=DATE-TIME:20230919T183000Z
DTEND;VALUE=DATE-TIME:20230919T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/94
DESCRIPTION:Title: G
ravitational Waves from NNaturalness\nby Akshay Ghalsasi (University o
f Pittsburgh) as part of NHETC Seminar\n\n\nAbstract\nNNaturalness provide
s a solution to the hierarchy problem by having large number of copies of
the standard model. The reheating mechanism is NNaturalness provides energ
y density to each of these sectors. The sectors in NNaturalness which have
a positive Higgs mass squared have massless quarks and hence can undergo
a first order phase transition. The resultant gravitational waves can be o
bservable by future gravitational wave observatories providing a unique wi
ndow into NNaturalness. I this talk\, I will describe the NNaturalness mec
hanism\, and the parameter space of NNaturalness that can be probed by fut
ure GW observatories.\n
LOCATION:https://researchseminars.org/talk/nhetc/94/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yitian Sun (MIT)
DTSTART;VALUE=DATE-TIME:20231026T183000Z
DTEND;VALUE=DATE-TIME:20231026T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/95
DESCRIPTION:by Yitian Sun (MIT) as part of NHETC Seminar\n\nAbstract: TBA\
n
LOCATION:https://researchseminars.org/talk/nhetc/95/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shu-Heng Shao (Stony Brook University)
DTSTART;VALUE=DATE-TIME:20231031T183000Z
DTEND;VALUE=DATE-TIME:20231031T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/96
DESCRIPTION:Title: N
on-invertible lattice translation\nby Shu-Heng Shao (Stony Brook Unive
rsity) as part of NHETC Seminar\n\n\nAbstract\nI will discuss non-invertib
le symmetries in 1+1d lattice models with a tensor-product Hilbert space\,
including the transverse-field Ising model and its deformation. The Krame
rs-Wannier duality operator on the lattice mixes with the lattice translat
ion\, and obeys a different non-invertible algebra compared to the continu
um one.\n
LOCATION:https://researchseminars.org/talk/nhetc/96/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ahsan Khan (IAS)
DTSTART;VALUE=DATE-TIME:20231214T193000Z
DTEND;VALUE=DATE-TIME:20231214T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/97
DESCRIPTION:Title: H
olomorphic Surface Defects in 4d Chern-Simons Theory and the Bethe Equatio
ns\nby Ahsan Khan (IAS) as part of NHETC Seminar\n\n\nAbstract\nThere
is a remarkable relationship between integrable systems in 1+1 dimensions
(such as the Heisenberg spin chain) and a certain quantum gauge theory in
four dimensions often referred to as four-dimensional Chern-Simons Theory.
I will review aspects of this relationship and then describe some newer r
esults involving holomorphic surface defects in this gauge theory and thei
r relationship to the Bethe equations governing spin chains.\n
LOCATION:https://researchseminars.org/talk/nhetc/97/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Brennan (UC San Diego)
DTSTART;VALUE=DATE-TIME:20231128T193000Z
DTEND;VALUE=DATE-TIME:20231128T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/98
DESCRIPTION:Title: T
he Callan Rubakov Effect\nby Daniel Brennan (UC San Diego) as part of
NHETC Seminar\n\n\nAbstract\nThe Callan Rubakov Effect describes the inter
action between (massless) fermions and a smooth monopole in 4d gauge theor
y. In this scenario\, the fermions can probe the UV physics inside the mon
opole core which leads to interesting effects such as proton decay in GUT
models. However\, the monopole-fermion scattering appears to lead to out-s
tates that are not in the perturbative Hilbert space. In this talk\, we wi
ll review this issue and propose a new physical mechanism that resolves th
is long-standing confusion.\n
LOCATION:https://researchseminars.org/talk/nhetc/98/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francois Lanusse (CNRS)
DTSTART;VALUE=DATE-TIME:20231205T193000Z
DTEND;VALUE=DATE-TIME:20231205T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/99
DESCRIPTION:by Francois Lanusse (CNRS) as part of NHETC Seminar\n\nAbstrac
t: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/99/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kevin Costello (Perimeter Institute)
DTSTART;VALUE=DATE-TIME:20231107T193000Z
DTEND;VALUE=DATE-TIME:20231107T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/100
DESCRIPTION:Title:
Burns space and celestial holography\nby Kevin Costello (Perimeter Ins
titute) as part of NHETC Seminar\n\n\nAbstract\nCelestial holography aims
to describe scattering amplitudes of theories on asymptotically flat space
times in terms of two-dimensional CFTs. I will describe an explicit top-d
own example\, where correlators of a 2d chiral CFT at large N match amplit
udes of a 4d theory on an asymptotically flat manifold known as Burns spac
e.\n
LOCATION:https://researchseminars.org/talk/nhetc/100/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lotte Hollands (Heriot-Watt University)
DTSTART;VALUE=DATE-TIME:20231219T193000Z
DTEND;VALUE=DATE-TIME:20231219T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/101
DESCRIPTION:Title:
Non-perturbative partition functions for N=2 theories of class S\nby L
otte Hollands (Heriot-Watt University) as part of NHETC Seminar\n\n\nAbstr
act\nThe beautiful works by Gaiotto\, Moore and Neitzke have taught us (in
particular) how to understand various kinds of BPS spectra for 4d N=2 the
ories in terms of certain configurations of curves on a Riemann surface\,
called spectral networks. In this talk I'll review how to generate a spect
ral network for each point of the 4d Coulomb branch together with the choi
ce of a phase. I'll point out that this data corresponds to a boundary con
dition for the 4d N=2 theory in the half-Omega background\, and associate
to it a new kind of N=2 partition function. This partition function is loc
ally constant in the phase\, while its jumps are associated to 4d BPS part
icles in the corresponding Coulomb vacuum. The well-known Nekrasov partiti
on function (in the half-Omega background) may be recovered in a weakly co
upled region of the Coulomb branch (if the theory admits any)\, at a speci
al phase corresponding to a Fenchel-Nielsen spectral network. When lifted
to five dimensions\, this new partition function becomes the non-perturbat
ive topological string partition function.\n
LOCATION:https://researchseminars.org/talk/nhetc/101/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zohar Komargodski (SCGP)
DTSTART;VALUE=DATE-TIME:20240123T193000Z
DTEND;VALUE=DATE-TIME:20240123T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/102
DESCRIPTION:Title:
The dynamics on Defects in Magnets and Gauge Theories\nby Zohar Komarg
odski (SCGP) as part of NHETC Seminar\n\n\nAbstract\nWe define a notion of
zero-temperature entropy for impurities (line defects) in d + 1 space-tim
e dimensions. We show that this entropy obeys a simple evolution equation
under the renormalization group. We apply this result for impurities in ma
gnets and in gauge theories. We find new critical impurities and phase tra
nsitions. We also discuss constraints from topology on the dynamics of def
ects and apply topology for the problem of spontaneous symmetry breaking a
nd the Kondo problem in a 2+1 dimensional quantum magnet.\n
LOCATION:https://researchseminars.org/talk/nhetc/102/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carolina Figueiredo (Princeton)
DTSTART;VALUE=DATE-TIME:20240130T193000Z
DTEND;VALUE=DATE-TIME:20240130T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/103
DESCRIPTION:Title:
Scalars to Pions and Gluons: New structure closer to the real world\nb
y Carolina Figueiredo (Princeton) as part of NHETC Seminar\n\n\nAbstract\n
Scattering amplitudes for the simplest theory of colored scalars— Tr phi
^3 theory — have been understood as arising from a counting problem asso
ciated with curves on a surface (arXiv:2309.15913v1). This formulation pro
duces “stringy” integrals for the amplitudes\, built off of variables
defined on the surface\, from which the field theory limit as $\\alpha^\\p
rime \\to 0$ can easily be extracted. In this talk\, we will extend this a
pproach to theories closer to the real world — in particular the non-lin
ear sigma model and Yang-Mills theory (arXiv:2401.00041v1). We will explai
n how amplitudes in these theories are surprisingly obtained from those of
the Tr $\\phi^3$ theory by simple shifts of the kinematic data. We will
also explain how these “stringy” formulations expose universal feature
s of the amplitudes present in all these colored theories — ranging from
hidden patterns of zeroes to unusual factorization properties away from s
ingularities (arXiv:2312.16282v1).\n
LOCATION:https://researchseminars.org/talk/nhetc/103/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ofer Aharony (Weizmann and IAS)
DTSTART;VALUE=DATE-TIME:20240213T193000Z
DTEND;VALUE=DATE-TIME:20240213T203000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/104
DESCRIPTION:Title:
Two dimensional QCD as a string theory\nby Ofer Aharony (Weizmann and
IAS) as part of NHETC Seminar\n\n\nAbstract\n50 years after the duality of
large N gauge theories to string theories was suggested\, we still do not
have a constructive method to find the string dual of a given gauge theor
y. I will review work in progress on two approaches to understanding this\
, in what should perhaps be the simplest case\, namely two dimensional gau
ge theories. The first approach uses perturbation theory to obtain an effe
ctive stringy description of the high-energy states of 2d QCD with very ma
ssive adjoint fermions. The second approach starts from finding a good wor
ldsheet description for the string dual to the two dimensional pure Yang-M
ills theory\, following past work by Gross-Taylor\, Cordes-Moore-Ramgoolam
\, and Horava\; in the future we hope to add to it boundaries (quarks in t
he fundamental representation) and/or extra particles on the worldsheet (a
djoint matter fields).\n
LOCATION:https://researchseminars.org/talk/nhetc/104/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francois Lanusse (CNRS)
DTSTART;VALUE=DATE-TIME:20240326T183000Z
DTEND;VALUE=DATE-TIME:20240326T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/105
DESCRIPTION:by Francois Lanusse (CNRS) as part of NHETC Seminar\n\nAbstrac
t: TBA\n
LOCATION:https://researchseminars.org/talk/nhetc/105/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Iñaki Garcia-Etxebarria (Durham\, UK)
DTSTART;VALUE=DATE-TIME:20240402T183000Z
DTEND;VALUE=DATE-TIME:20240402T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/106
DESCRIPTION:Title:
Deriving SymTFTs from geometry\nby Iñaki Garcia-Etxebarria (Durham\,
UK) as part of NHETC Seminar\n\n\nAbstract\nSymTFTs (or\, relatedly\, the
"sandwich construction") have emerged recently as a useful way to think of
categorical symmetries. I will give a brief description of this construct
ion\, and then review recent work on how to obtain the SymTFT data from ge
ometry in the context of geometric engineering.\n
LOCATION:https://researchseminars.org/talk/nhetc/106/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ibrahima Bah (Johns Hopkins)
DTSTART;VALUE=DATE-TIME:20240423T183000Z
DTEND;VALUE=DATE-TIME:20240423T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/107
DESCRIPTION:Title:
Aspects of topological symmetry\, holography\, and branes\nby Ibrahima
Bah (Johns Hopkins) as part of NHETC Seminar\n\nInteractive livestream: h
ttps://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRPdz09\
n\nAbstract\nIn this talk I will discuss the holographic duals of topologi
cal operators. At low energy sugra\, they can be realized by Page charge
associated to Gauss law constraints. In the UV string theory\, topologica
l operators can be characterized by various brane configurations. This pr
ovides a way of exploring generalized symmetries with dynamical bulk physi
cs.\n
LOCATION:https://researchseminars.org/talk/nhetc/107/
URL:https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRP
dz09
END:VEVENT
BEGIN:VEVENT
SUMMARY:Iñaki Garcia-Etxebarria (Durham)
DTSTART;VALUE=DATE-TIME:20240507T183000Z
DTEND;VALUE=DATE-TIME:20240507T193000Z
DTSTAMP;VALUE=DATE-TIME:20240423T114727Z
UID:nhetc/108
DESCRIPTION:Title:
Deriving SymTFTs from geometry\nby Iñaki Garcia-Etxebarria (Durham) a
s part of NHETC Seminar\n\nInteractive livestream: https://rutgers.zoom.us
/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRPdz09\n\nAbstract\nSymTFTs (
or\, relatedly\, the "sandwich construction") have emerged recently as a u
seful way to think of categorical symmetries. I will give a brief descript
ion of this construction\, and then review recent work on how to obtain th
e SymTFT data from geometry in the context of geometric engineering.\n
LOCATION:https://researchseminars.org/talk/nhetc/108/
URL:https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRP
dz09
END:VEVENT
END:VCALENDAR