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BEGIN:VEVENT
SUMMARY:Aswin Balasubramanian (Rutgers)
DTSTART:20200512T190000Z
DTEND:20200512T200000Z
DTSTAMP:20260404T111008Z
UID:nhetc/1
DESCRIPTION:Title: Families of Hitchin systems and N=2 theories\nby Aswin Balasubram
anian (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 robust exchange of ideas between physics and mathematics. In my talk
\, I will explain how to extend this dictionary to one between 4d N=2 phys
ics and the SL_N Hitchin system on a nodal UV Curve. I will then use this
dictionary to clarify certain questions concerning Coulomb branches of the
corresponding Class S theories at various boundaries of the space of marg
inal parameters. In mathematical terms\, I will describe tame SL_N Hitchin
systems as a flat family of integrable systems over \\bar{M}\, the Delign
e-Mumford moduli space of the UV Curve. This is based on upcoming work wit
h J. Distler and R. Donagi.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ahsan Khan (Rutgers University)
DTSTART:20201013T190000Z
DTEND:20201013T200000Z
DTSTAMP:20260404T111008Z
UID:nhetc/2
DESCRIPTION:Title: Domain Wall Junctions and Categorical Wall-Crossing\nby Ahsan Kha
n (Rutgers University) as part of NHETC Seminar\n\n\nAbstract\nThe wall-cr
ossing property of BPS states is an important feature common to centrally
extended supersymmetric field theories. In this talk I will describe how t
he physics of domain wall junctions combined with elementary ideas in homo
logical algebra leads to a categorical wall-crossing formula\; a universal
description of how BPS Hilbert spaces jump across a wall of marginal stab
ility. \n\nBased on an upcoming paper with Greg Moore.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ibrahima Bah (Johns Hopkins University)
DTSTART:20201027T190000Z
DTEND:20201027T200000Z
DTSTAMP:20260404T111008Z
UID:nhetc/3
DESCRIPTION:Title: Anomaly Inflow and topological mass terms\nby Ibrahima Bah (Johns
Hopkins 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 wi
ll consider QFTs obtained from brane setups in supergravity and discuss ho
w the presence of bulk topological mass terms are responsible for several
interesting features of the anomaly for the QFTs. In particular I will di
scuss how these terms encode the anomalies for discrete symmetries.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sergei Gukov (Caltech)
DTSTART:20201103T200000Z
DTEND:20201103T210000Z
DTSTAMP:20260404T111008Z
UID:nhetc/4
DESCRIPTION:Title: Cobordism invariants from BPS q-series\nby Sergei Gukov (Caltech)
as part of NHETC Seminar\n\n\nAbstract\nMany BPS partition functions depe
nd 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 o
f Spin^c structure we show how different limits with respect to the expans
ion variable q and different ways of summing over Spin^c structures produc
e different invariants of homology cobordisms out of the BPS q-series. Bas
ed on a recent work with Pavel Putrov and Sunghyuk Park.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cristina Mondino (Perimeter Institute)
DTSTART:20210223T180000Z
DTEND:20210223T190000Z
DTSTAMP:20260404T111008Z
UID:nhetc/5
DESCRIPTION:Title: Probing dark matter substructure with astrometric weak lensing\nb
y Cristina Mondino (Perimeter Institute) as part of NHETC Seminar\n\n\nAbs
tract\nLow-mass structures of dark matter are expected to be entirely devo
id of light-emitting regions and baryons. Precisely because of this lack o
f baryonic feedback\, small-scale substructures of the Milky Way are a rel
atively pristine testing ground for discovering aspects of dark matter mic
rophysics and primordial fluctuations on sub-galactic scales. I will prese
nt results from the first search for galactic dark matter subhalos with ti
me-domain astrometric weak gravitational lensing. The analysis is based on
a matched-filter template of local lensing corrections to the proper moti
on of stars in the Magellanic Clouds and is most sensitive to compact dark
structures of ten million to a hundred million solar mass.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicholas Rodd (UC Berkeley)
DTSTART:20210309T180000Z
DTEND:20210309T190000Z
DTSTAMP:20260404T111008Z
UID:nhetc/6
DESCRIPTION:Title: Two new ideas for the axion dark matter program\nby Nicholas Rodd
(UC Berkeley) as part of NHETC Seminar\n\n\nAbstract\nThe coming decade w
ill bring dramatic improvement in the axion dark matter program as new exp
erimental designs move beyond the proof of principle stage. In this talk I
will outline two new ideas that exploit this experimental progress. The f
irst is to combine the results from two or more instruments in order to pe
rform interferometry directly on the dark-matter wave. This technique reve
als aspects 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 t
o search for relativistic axions in these experiments\, in particular futu
re instruments 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 cosmic relic\, although if relativistic axions are produce in the late
universe\, by for instance dark-matter decaying to axions\, then this is a
signal the experiments are already sensitive to\, but would miss with exi
sting analyses.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Phiala Shanahan (MIT)
DTSTART:20210323T170000Z
DTEND:20210323T180000Z
DTSTAMP:20260404T111008Z
UID:nhetc/7
DESCRIPTION:Title: Machine learning for physics: gauge-equivariant architectures\nby
Phiala Shanahan (MIT) as part of NHETC Seminar\n\n\nAbstract\nAs machine
learning algorithms continue to enable and accelerate physics calculations
in novel ways\, the development of tailored physics-informed machine lear
ning approaches is becoming more sophisticated\, impactful\, and important
. I will give some broad context for this developing area\, with a focus o
n the challenge of exact sampling from known probability distributions as
relevant to lattice quantum field theory calculations in particle and nucl
ear physics. I will discuss in particular flow-based generative models\, a
nd describe how guarantees of exactness and the incorporation of complex s
ymmetries (e.g.\, gauge symmetry) into model architectures can be achieved
. I will show the results of proof-of-principle studies that demonstrate t
hat sampling from generative models can be orders of magnitude more effici
ent than traditional Hamiltonian/hybrid Monte Carlo approaches in this con
text.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ken Van Tilburg (NYU/Flatiron CCA)
DTSTART:20210406T170000Z
DTEND:20210406T180000Z
DTSTAMP:20260404T111008Z
UID:nhetc/8
DESCRIPTION:Title: Stellar Basins of Gravitationally Bound Particles\nby Ken Van Til
burg (NYU/Flatiron CCA) as part of NHETC Seminar\n\n\nAbstract\nI will des
cribe and explore the consequences of a peculiar physical phenomenon: volu
metric stellar emission into gravitationally bound orbits of weakly couple
d particles such as axions\, moduli\, hidden photons\, and neutrinos. Whil
e only a tiny fraction of the instantaneous luminosity of a star (the vast
majority of the emission is into relativistic modes)\, the continual inje
ction of these particles into a small part of phase space causes them to a
ccumulate over astrophysically long time scales\, forming what I call a "s
tellar basin"\, in analogy with the geologic kind. The energy density of t
he Solar basin can surpass that of the relativistic Solar flux at Earth's
location after only a million years\, for any sufficiently long-lived part
icle produced through an emission process whose matrix elements are unsupp
ressed at low momentum. This observation has immediate and striking conseq
uences for direct detection experiments---including new limits on axion an
d hidden-photon parameter space independent of dark matter assumptions---a
nd opens up prospects for indirect detection of weakly interacting particl
es around stars. [Based on https://arxiv.org/abs/2006.12431 and https://ar
xiv.org/abs/2008.08594\, and ongoing work.]\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jeff Dror (UC Santa Cruz)
DTSTART:20210420T170000Z
DTEND:20210420T180000Z
DTSTAMP:20260404T111008Z
UID:nhetc/9
DESCRIPTION:Title: Testing 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 sendin
g a beam of light at our telescopes. The arrival time of each pulse is dep
endent on the Earth's motion\, opening an opportunity to search for gravit
ational waves shaking the Earth with frequencies of O(year^-1). In this ta
lk\, I will show how these datasets can be used to probe fundamental physi
cs focusing both on types of signals to search for as well as how recent d
evelopments in machine learning can be employed to greatly expand the rang
e of searches carried out by pulsar timing experiments. These searches are
particularly timely due to the recent detection of a correlated signal ac
ross many pulsars\, which may be our first glimpse of gravitational waves
from supermassive black hole mergers.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jared Kaplan (Johns Hopkins University)
DTSTART:20210126T183000Z
DTEND:20210126T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/10
DESCRIPTION:Title: Scaling Laws in Machine Learning and GPT-3\nby Jared Kaplan (Joh
ns Hopkins University) as part of NHETC Seminar\n\n\nAbstract\nA variety o
f recent works suggest that scaling laws are ubiquitous in machine learnin
g. In particular\, neural network performance obeys scaling laws with res
pect to the number of parameters\, dataset size\, and the training compute
budget. I will explain these scaling laws\, and argue that they are both
precise and very universal. Then I will explain how this line of thinkin
g led to the GPT-3 language model\, and what it suggests for the future.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Harikrishnan Ramani (Stanford University)
DTSTART:20210209T183000Z
DTEND:20210209T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/11
DESCRIPTION:Title: Tackling energy deficits for dark matter detection\nby Harikrish
nan Ramani (Stanford University) as part of NHETC Seminar\n\n\nAbstract\nM
odels such as inelastic dark matter\, dark matter with large interactions
with the standard model\, and dark matter with masses below 1 MeV are noto
riously difficult to detect in direct detection experiments owing to their
inability to impart a large enough recoil energy in traditional dark matt
er experiments. In this talk\, I explore different strategies to attack th
is problem. These include nuclear isomer batteries\, electric fields to ac
celerate milli-charge dark matter and atoms and molecules with small energ
y gaps.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emil Martinec (University of Chicago)
DTSTART:20210413T170000Z
DTEND:20210413T180000Z
DTSTAMP:20260404T111008Z
UID:nhetc/12
DESCRIPTION:Title: Stringy Structure at the BPS Bound\nby Emil Martinec (University
of Chicago) as part of NHETC Seminar\n\n\nAbstract\nWorldsheet string the
ory paints 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 descriptio
n in terms of gauged WZW models to explore the stringy properties of these
states. Consequences for black hole formation will also be discussed.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brian Nord (Fermilab)
DTSTART:20210504T170000Z
DTEND:20210504T180000Z
DTSTAMP:20260404T111008Z
UID:nhetc/13
DESCRIPTION:Title: Deeply Uncertain: (how) can we make deep learning tools trustworthy
for scientific measurements?\nby Brian Nord (Fermilab) as part of NHET
C Seminar\n\n\nAbstract\nArtificial Intelligence (AI) --- including machin
e learning and deep learning --- refers to a set of techniques that rely p
rimarily on the data itself for the construction of a quantitative model.
AI has been in development for about three quarters of a century\, but the
re has been a recent resurgence in research and applications. This current
(third) wave of AI progress is marked by extraordinary results --- for ex
ample\, in image analysis\, language translation\, and machine automation.
Despite the modest definition of AI\, its potential to disrupt technologi
es\, economies\, society\, and even science is often presented as unmatche
d in modern times. However\, along with the promise of AI\, there are sign
ificant challenges to overcome to reach a degree of reliability that is on
par with more traditional modeling methods. \nIn particular\, uncertainty
quantification metrics derived from deep neural networks are yet to be ma
de physically interpretable. For example\, when one uses a convolutional n
eural network to measure values from an image (e.g.\, regression for galax
y properties)\, the error estimates do not necessarily match those from an
MCMC likelihood fit. In this presentation\, I will discuss the landscape
of uncertainty quantification in deep learning\, as well as some computati
onal experiments in a physical context that demonstrate a mismatch between
errors derived directly from deep learning methods and those derived thro
ugh traditional error propagation. Before we can apply deep learning tools
confidently for the direct measurement of physical properties\, we’ll n
eed statistically robust error estimation methods.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tongyan Lin
DTSTART:20210907T170000Z
DTEND:20210907T180000Z
DTSTAMP:20260404T111008Z
UID:nhetc/14
DESCRIPTION:Title: Dark matter direct detection with dielectrics\nby Tongyan Lin as
part of NHETC Seminar\n\n\nAbstract\nDirect detection experiments are rap
idly advancing in the search for sub-GeV dark matter. As energy thresholds
become lower\, the many-body physics of a target material becomes especia
lly important in determining a dark matter signal. In this talk\, I will d
iscuss how dark matter interactions in dielectric materials can be underst
ood in terms of the dielectric response\, or energy loss function (ELF). T
his provides a useful framework for dark matter direct detection and also
allows us to calculate some new effects. I will discuss various applicatio
ns of this\, including screening effects for dark matter electron scatteri
ng\, phonon creation\, and the Migdal effect in semiconductors.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shu-Heng Shao (YITP\, Stony Brook University)
DTSTART:20210914T170000Z
DTEND:20210914T180000Z
DTSTAMP:20260404T111008Z
UID:nhetc/15
DESCRIPTION:Title: On topological boundary conditions in 2+1d TQFT\nby Shu-Heng Sha
o (YITP\, Stony Brook University) as part of NHETC Seminar\n\n\nAbstract\n
A 2+1-dimensional topological quantum field theory (TQFT) may or may not a
dmit topological (gapped) boundary conditions. In this talk\, we consider
obstructions to the existence of a topological boundary condition from the
"higher" central charges\, which have been introduced recently in the mat
h literature. In terms of these new obstructions\, we identify necessary a
nd sufficient conditions for the existence of a topological boundary in th
e case of bosonic\, Abelian TQFTs\, providing an alternative to the identi
fication of a Lagrangian subgroup. Our proof relies on general aspects of
gauging generalized global symmetries.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Whiteson (University of California\, Irvine)
DTSTART:20210921T170000Z
DTEND:20210921T180000Z
DTSTAMP:20260404T111008Z
UID:nhetc/16
DESCRIPTION:Title: Learning Particle Physics from Machines\nby Daniel Whiteson (Uni
versity of California\, Irvine) as part of NHETC Seminar\n\n\nAbstract\nRe
cent advances in artificial intelligence offer opportunities to disrupt th
e traditional strategies for discovery of new particles in high energy col
lisions. I will describe the new machine-learning techniques\, explain wh
y they are particularly well suited for particle physics\, present selecte
d results that demonstrate their new capabilities\, and present a strategy
for translating their learned strategies into human understanding. \n\
nBio: Daniel Whiteson is a professor of experimental particle physics at t
he University of California\, Irvine\, and a fellow of the American Physic
al Society. He conducts research using the Large Hadron Collider at CERN.
He received his PhD at Berkeley.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John McGreevy (University of California\, San Diego)
DTSTART:20210928T183000Z
DTEND:20210928T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/17
DESCRIPTION:Title: Fractons and Chern-Simons Theory\nby John McGreevy (University o
f California\, San Diego) as part of NHETC Seminar\n\n\nAbstract\nAfter di
scussing some reasons that fractons are interesting\, I will talk about a
version of dimensional deconstruction that produces 3+1d fracton phases. T
his construction provides examples beyond those known from solvable lattic
e models\, and a possible route to realize them in experiments.\n\nBased o
n 2010.08917 with Xiuqi Ma\, Wilbur Shirley\, Meng Cheng\, Michael Levin a
nd Xie Chen.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Harlow (MIT)
DTSTART:20211012T160000Z
DTEND:20211012T170000Z
DTSTAMP:20260404T111008Z
UID:nhetc/18
DESCRIPTION:Title: A universal formula for the density of states in theories with finit
e-group symmetry\nby Daniel Harlow (MIT) as part of NHETC Seminar\n\n\
nAbstract\nIn this paper we use Euclidean gravity to derive a simple formu
la for the density of black hole microstates which transform in each irred
ucible representation of any finite gauge group. Since each representation
appears with nonzero density\, this\ngives a new proof of the completenes
s hypothesis for finite gauge fields. Inspired by the generality of the ar
gument we further propose that the formula applies at high energy in any q
uantum field theory with a finite-group global symmetry\, and give some ev
idence for this conjecture.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Davide Gaiotto (Perimeter Institute)
DTSTART:20211026T183000Z
DTEND:20211026T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/19
DESCRIPTION:Title: Giant gravitons in twisted holograpy\nby Davide Gaiotto (Perimet
er Institute) as part of NHETC Seminar\n\n\nAbstract\nI will demonstrate t
he emergence of bulk geometric structures in a simple\, essentially free\,
toy model for holography.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ofri Telem (LBNL Physics Division)
DTSTART:20211102T183000Z
DTEND:20211102T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/20
DESCRIPTION:Title: Monopole Catalysis From Scattering Amplitudes\nby Ofri Telem (LB
NL Physics Division) as part of NHETC Seminar\n\n\nAbstract\nUsing our nov
el construction of the S-matrix for the scattering of electric and magneti
c charges\, we address the notoriously confusing effect of Monopole Cataly
sis. In particular\, we provide an on-shell derivation of the Rubakov-Call
an effect\, as well as address the famous “monopole unitarity paradox”
- where there seems to be no valid final state in the scattering of a pos
itron with a GUT monopole. Our proposed final state involves 3 fermions wi
th total J=0\, which conserve all SM quantum numbers and can escape the co
re by virtue of their entanglement with the monopole.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brian Swingle (MIT)
DTSTART:20211109T193000Z
DTEND:20211109T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/21
DESCRIPTION:Title: Hydrodynamics and the Spectral Form Factor\nby Brian Swingle (MI
T) as part of NHETC Seminar\n\n\nAbstract\nEnsembles of quantum chaotic sy
stems are expected to exhibit random matrix universality in their energy s
pectrum. The presence of this universality can be diagnosed by looking for
a linear in time 'ramp' in the spectral form factor\, but for realistic s
ystems this feature is typically only visible after a sufficiently long ti
me. It is important to understand the emergence of this universality and h
ow it connects to the larger body of phenomena associated with quantum cha
os. This talk will present a hydrodynamic theory of the spectral form fact
or in systems with slow modes. The formalism predicts the linear ramp at s
ufficiently late time and gives a quantitative framework for computing the
approach to ramp.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Katelin Schutz (McGill Space Institute)
DTSTART:20211116T193000Z
DTEND:20211116T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/22
DESCRIPTION:Title: Astrophysical plasmas\, phase space\, and searches for new particles
\nby Katelin Schutz (McGill Space Institute) as part of NHETC Seminar\
n\n\nAbstract\nAstrophysical plasmas can be an abundant source of particle
s with a small coupling to photons\, for instance in dark sectors with a k
inetically mixed U(1). In many situations\, the decay of plasmons (photons
with an in-medium effective mass) is the most efficient process for gener
ating new kinds of particles. In this talk\, I will discuss two distinct e
xamples: the production of gravitationally bound particles in the sun and
the freeze-in of dark matter in the early Universe. In the former case\, I
will show how gravitationally bound particles from the sun may be detecta
ble with an experimental setup that coherently deflects the solar MCP wind
\, generating an oscillating electric field in a shielded detector. In the
latter case\, I will show that dark matter freeze-in from plasmon decay m
ay be detectable through its cosmological clustering and through a drag ef
fect imparted on the photon-baryon fluid prior to recombination. If there
is sufficient time\, I will also discuss the detection of axion dark matte
r decay that is stimulated by the synchrotron radiation coming from the pl
asma suffusing supernova remnants. In all of these examples\, the unique p
hase space of new particles provides the main observational handle for dis
covery.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoff Penington (UC Berkeley)
DTSTART:20211130T193000Z
DTEND:20211130T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/24
DESCRIPTION:Title: Quantum minimal surfaces from quantum error correction\nby Geoff
Penington (UC Berkeley) as part of NHETC Seminar\n\n\nAbstract\nWe show t
hat complementary state-specific reconstruction of logical (bulk) operator
s is equivalent to the existence of a quantum minimal surface prescription
for physical (boundary) entropies. This significantly generalizes both si
des of an equivalence previously shown by Harlow\; in particular\, we do n
ot require the entanglement wedge to be the same for all states in the cod
e space. In developing this theorem\, we construct an emergent bulk geomet
ry for general quantum codes\, defining "areas" associated to arbitrary lo
gical subsystems\, and argue that this definition is "functionally unique.
" We also formalize a definition of bulk reconstruction that we call "stat
e-specific product unitary" reconstruction. This definition captures the q
uantum error correction (QEC) properties present in holographic codes and
has potential independent interest as a very broad generalization of QEC\;
it includes most traditional versions of QEC as special cases. Our result
s extend to approximate codes\, and even to the "non-isometric codes" that
seem to describe the interior of a black hole at late times.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rebecca Leane (SLAC)
DTSTART:20211207T193000Z
DTEND:20211207T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/25
DESCRIPTION:Title: Detecting Dark Matter in Celestial Bodies\nby Rebecca Leane (SLA
C) as part of NHETC Seminar\n\n\nAbstract\nStars and planets can be ideal
playgrounds to discover dark matter. In this talk\, I will review a range
of dark matter searches using celestial objects\, including neutron stars\
, exoplanets\, solar-system planets\, and our Sun. I will discuss differen
t search strategies\, their opportunities and limitations\, and the interp
lay of regimes where different celestial objects are optimal detectors.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Patrick Draper (University of Illinois)
DTSTART:20211005T183000Z
DTEND:20211005T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/26
DESCRIPTION:Title: The CKN Bound and Particle Physics\nby Patrick Draper (Universit
y of Illinois) as part of NHETC Seminar\n\n\nAbstract\nThe holographic pri
nciple implies that quantum field theory overcounts the number of independ
ent degrees of freedom in quantum gravity. An argument due to Cohen\, Kapl
an\, and Nelson (CKN) suggests that the number of degrees of freedom well-
described by QFT is even smaller than required by holographic bounds\, and
CKN interpreted this result as indicative of a correlation between the UV
and IR cutoffs on QFT. We consider an alternative interpretation in which
the QFT degrees of freedom are depleted as a function of scale\, and we u
se a simple recipe to estimate the impact of depleted densities of states
on precision observables. Although these observables are not sensitive to
the level of depletion motivated by gravitational considerations\, the phe
nomenological exercises also provide an interesting test of QFT that is in
dependent of underlying quantum gravity assumptions. A depleted density of
states can also render the QFT vacuum energy UV-insensitive\, reconciling
the success of QFT in describing ordinary particle physics processes and
its apparent failure in predicting the cosmological constant.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Siddharth Mishra-Sharma (MIT)
DTSTART:20211019T183000Z
DTEND:20211019T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/27
DESCRIPTION:Title: Using machine learning to look for dark matter in the Galactic Cente
r\, the Milky Way halo\, and other galaxies\nby Siddharth Mishra-Sharm
a (MIT) as part of NHETC Seminar\n\n\nAbstract\nAdvancements in machine le
arning have enabled new ways of doing inference on forward models defined
through complex\, high-dimensional simulations. After briefly motivating t
heir use in the cosmological context\, I will present applications of thes
e simulation-based inference methods to three separate astrophysical syste
ms with the goal of looking for signatures of dark matter. First\, I will
describe how they can be used to combine information from thousands of str
ong gravitational lensing systems in a principled way in order to extract
the population properties of dark matter. Then\, I will quantify their sen
sitivity to the collective imprint of dark matter subhalos in our own Gala
xy on the measured motions of background luminous celestial objects. Final
ly\, I will present an application to the Galactic Center gamma-ray excess
\, where the fact that our method can extract more information from the ga
mma-ray dataset than is possible with traditional techniques can be used t
o more robustly characterize the nature of the excess and constrain its da
rk matter properties.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juven Wang (Harvard)
DTSTART:20211123T193000Z
DTEND:20211123T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/28
DESCRIPTION:Title: Quantum Criticality Beyond the Standard Model and Ultra Unification<
/a>\nby Juven Wang (Harvard) as part of NHETC Seminar\n\n\nAbstract\nWe pr
opose a theory [arXiv:2012.15860] beyond the Standard Model (SM) and Grand
Unification (GUT) with 15n Weyl fermions by adding new gapped Topological
Phase Sectors based on nonperturbative global anomaly cancellations and c
obordism constraints (especially from the baryon minus lepton number B −
L \, the electroweak hypercharge Y\, and the Z_{16} class mixed gauge-gra
vitational anomaly). Gapped topological phase sectors are constructed via
symmetry extension (in contrast with the Anderson-Higgs symmetry breaking)
\, whose low energy contains unitary Lorentz invariant topological quantum
field theories (TQFTs): either (3+1)d noninvertible TQFT\, or (4+1)d inve
rtible or noninvertible TQFT (short-range or long-range entangled gapped p
hase). Alternatively\, there could also be right-handed neutrinos\, or gap
less unparticle conformal field theories\, or their combinations to altoge
ther cancel the mixed gauge-gravitational anomaly. We also introduce an al
ternative view [arXiv:2106.16248] that the SM is a low-energy quantum vacu
um arising from various neighbor GUT vacua competition in an immense quant
um phase diagram. In particular\, we demonstrate how the su(3)×su(2)×u(1
) SM with 16n Weyl fermions arose near the quantum criticality between the
competition of Georgi-Glashow su(5) model and Pati-Salam su(4)×su(2)×su
(2) model. Moreover\, to manifest a Beyond-the-Standard-Model (BSM) and Be
yond-Landau-Ginzburg deconfined quantum criticality between Georgi-Glashow
and Pati-Salam models\, we introduce a parent effective field theory of a
modified 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 g
lobal mixed gauge-gravity anomaly captured by a 5d invertible topological
field theory w2w3(TM)=w2w3(VSO(10)). We show new fractionalized excitation
s of Color-Flavor separation\, and gauge enhancement including a Dark Gaug
e force sector\, or gauge-enhanced 4d criticality as a boundary criticalit
y such that only appropriately gauge enhanced dynamical GUT gauge fields c
an propagate into an extra-dimensional 5d bulk.\n\nThe talk is mainly base
d on arXiv:2012.15860\, arXiv:2106.16248\, and arXiv:2111.10369 (with Yi-Z
huang You).\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anton Kapustin (Caltech)
DTSTART:20220222T193000Z
DTEND:20220222T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/29
DESCRIPTION:Title: Equivariant Berry phase for many-body quantum lattice systems\nb
y Anton Kapustin (Caltech) as part of NHETC Seminar\n\n\nAbstract\nBerry p
hase as originally defined makes sense only for quantum systems with a fin
ite-dimensional Hilbert space. However\, it does have important generaliza
tions to many-body systems. In this talk I will describe some generalizati
ons 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
- Wigner theorem on level crossing in quantum systems.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hank Lamm (Fermilab)
DTSTART:20220201T193000Z
DTEND:20220201T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/30
DESCRIPTION:Title: Quantum Computing for Quantum Field Theories\nby Hank Lamm (Ferm
ilab) as part of NHETC Seminar\n\n\nAbstract\nThe advent of quantum comput
ation presents the opportunity to solve questions in physics which are ina
ccessible to classical computation such as real-time evolution and the equ
ation of state at finite density. In order to take advantage of this new r
esource\, a number of theoretical and computational hurdles will need to b
e addressed. In this talk\, I will discuss the state of the art research
being performed in quantum field theory and outstanding questions that req
uire our attention going forward\, focusing on digitization of lattice gau
ge theories and extracting physical results that demonstrate practical qua
ntum advantage.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Graham White (University of Tokyo)
DTSTART:20220215T213000Z
DTEND:20220215T223000Z
DTSTAMP:20260404T111008Z
UID:nhetc/31
DESCRIPTION:Title: Archaeology on the origin of matter\nby Graham White (University
of Tokyo) as part of NHETC Seminar\n\n\nAbstract\nOne of the most convinc
ing reasons to expect physics beyond\nthe Standard model is the inbalance
between matter and anti-matter. Some\nfantastic paradigms exist that can b
e probed at a low scale including\nelectroweak baryogenesis\, mesogenesis
and resonant leptogenesis. While\nthese paradigms or worthy of dedicated a
ttention\, the elephant in the\nroom is that there are two paradigms that
are very minimal and involve\nphysics at scales we cannot possibly reach w
ith Earth based colliders in\nour life time. I will first discuss the nigh
tmare scenario of thermal\nleptogenesis implemented with no BSM particle c
ontent beyond sterile\nneutrinos and an inflaton. In this case\, measureme
nts of the top and\nHiggs mass along with inflationary observables can she
d some light on\nthe plausibility\, or lack thereof\, of vanilla leptogene
sis. I will then\ndiscuss the GUT leptogenesis and Affleck Dine baryogenes
is. I argue in\nboth these cases there are generic predictions of a primor
dial\ngravitational wave background that can be measured today. The presen
ce\nof such a signal would lend plausibility to one of these scenarios.\nF
inally I discuss the discriminating power of GWs in discerning the\nsymme
try breaking path through the variable signals of hybrid defects.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Clara Murgui (Caltech)
DTSTART:20220301T193000Z
DTEND:20220301T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/32
DESCRIPTION:Title: Dark Unification: a UV-complete Theory of Asymmetric Dark Matter
\nby Clara Murgui (Caltech) as part of NHETC Seminar\n\n\nAbstract\nMotiva
ted by the observed ratio of dark matter to baryon mass densities\, which
is around a factor 5\, we propose a theory of dark-color unification. In t
his theory\, the dark to visible baryon masses are fixed by the ratio of d
ark to visible confinement scales\, which are determined to be nearby in m
ass through the unification of the dark and visible gauge theories at a hi
gh scale. Together with a mechanism for darko-baryo-genesis\, which arises
naturally from the grand unification sector\, the mass densities of the t
wo sectors must be nearby\, explaining the observed mass density of dark m
atter. We focus on the simplest possible example of such a theory\, where
Standard Model color SU(3)c is unified with dark color SU(2)D into SU(5) a
t an intermediate 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 i
mportant cosmological\, astrophysical and collider signatures to explore\,
including dark matter self-interactions\, early matter domination from th
e dark hadrons\, gravitational wave signatures from the hidden sector phas
e transition\, contributions to flavor observables\, as well as Hidden Val
ley-like signatures at colliders.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tudor Dimofte (UC Davis and University of Edinburgh)
DTSTART:20220308T193000Z
DTEND:20220308T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/33
DESCRIPTION:Title: A QFT for non-semisimple TQFT\nby Tudor Dimofte (UC Davis and Un
iversity 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 construc
ted in the 90's (by Lyubashenko and others) from representation categories
of small quantum groups at roots of unity\; they were recently generalize
d in work of Costantino-Geer-Patureau Mirand and collaborators. I will int
roduce a family of physical 3d quantum field theories that (conjecturally)
reproduce these classic non-semisimple TQFT's. The physical theories comb
ine Chern-Simons-like and 3d N=4-like sectors. They are also related to Fe
igin-Tipunin vertex algebras\, much the same way that Chern-Simons theory
is related to WZW vertex algebras.\n(Based on work with T. Creutzig\, N. G
arner\, and N. Geer.)\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Greg Yang (Microsoft Research)
DTSTART:20220322T183000Z
DTEND:20220322T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/34
DESCRIPTION:Title: Renormalizing the Optimal Hyperparameters of a Neural Network\nb
y Greg Yang (Microsoft Research) as part of NHETC Seminar\n\n\nAbstract\nH
yperparameter tuning in deep learning is an expensive process\, prohibitiv
ely so for neural networks (NNs) with billions of parameters that often ca
n 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 abl
e to re-tune the 6.7-billion-parameter model of GPT-3 and obtain performan
ce comparable to the 13-billion-parameter model of GPT-3\, effectively dou
bling the model size.\n\nIn this context\, there is a rich analogy we can
make to Wilsonian effective field theory. For example\, if “coupling con
stants” in physics correspond to “optimal hyperparameters” in deep l
earning and “cutoff scale” corresponds to “model size”\, then we c
an say “μP is a renormalizable theory of neural networks.” We finish
by formulating the question of whether there is a “Grand Unifying Theory
” of neural networks at scale that can inform our quest toward general i
ntelligence.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andy Neitzke (Yale University)
DTSTART:20220329T183000Z
DTEND:20220329T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/35
DESCRIPTION:Title: Differential equations and deformations of supersymmetric QFT\nb
y Andy Neitzke (Yale University) as part of NHETC Seminar\n\n\nAbstract\nT
here is a connection between N=2 supersymmetric field theory in four dimen
sions and the theory of linear differential and difference equations with
meromorphic coefficients. This connection is surprisingly rich\, and has b
een studied by many different authors from different perspectives. One way
of understanding it is as an instance of the general phenomenon that turn
ing on Omega-background naturally quantizes algebraic structures in the op
erator algebras of supersymmetric QFT. I will recall this connection and d
escribe some of its uses\, along with some recent and ongoing extensions o
f the story.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ian Moult (Yale University)
DTSTART:20220405T183000Z
DTEND:20220405T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/36
DESCRIPTION:Title: Conformal Colliders Meet the LHC\nby Ian Moult (Yale University)
as part of NHETC Seminar\n\n\nAbstract\nJets of hadrons produced at high-
energy colliders provide experimental access to the dynamics of asymptotic
ally free quarks and gluons and their confinement into hadrons. Motivated
by recent developments in conformal field theory\, we propose a reformulat
ion of jet substructure as the study of correlation functions of a specifi
c class of light-ray operators and their associated operator product expan
sion (OPE). We show that multi-point correlation functions of these operat
ors can be measured in real LHC data\, allowing us to experimentally verif
y properties of the light-ray OPE. We then discuss how this reformulation
provides new ways of experimentally studying the Standard Model at collide
rs\, as well as new theoretical techniques for performing calculations in
QCD.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Du Pei (Harvard)
DTSTART:20220412T183000Z
DTEND:20220412T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/37
DESCRIPTION:Title: Holomorphic CFTs and topological modular forms\nby Du Pei (Harva
rd) as part of NHETC Seminar\n\n\nAbstract\nThe theory of topological modu
lar forms leads to many interesting constraints and predictions for two-di
mensional quantum field theories. In this talk\, I will show that a conjec
ture by Segal\, Stolz and Teichner requires the constant term of the parti
tion function of a bosonic holomorphic CFTs to be divisible by specific in
tegers determined by the central charge. We verify this constraint in larg
e classes of physical examples\, and rule out the existence of an infinite
set of "extremal CFTs"\, including those with central charges c = 48\, 72
\, 96 and 120.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joshua Isaacson (Fermilab)
DTSTART:20220419T183000Z
DTEND:20220419T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/38
DESCRIPTION:Title: How to measure M_W: A theory perspective\nby Joshua Isaacson (Fe
rmilab) as part of NHETC Seminar\n\n\nAbstract\nWith the recent CDF-II W m
ass measurement\, many questions have arisen about the accuracy and proced
ure of extracting the W mass. In this talk\, I will cover the details of t
he ResBos calculation used by the CDF experiment\, along with details on t
he procedure of extracting the W mass and the associated theory uncertaint
ies.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pietro Longhi (Uppsala University)
DTSTART:20220426T183000Z
DTEND:20220426T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/39
DESCRIPTION:Title: Studies of five-dimensional BPS spectra and applications to enumerat
ive geometry\nby Pietro Longhi (Uppsala University) as part of NHETC S
eminar\n\n\nAbstract\nThe framework of spectral networks was introduced in
physics 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 n
etworks\, which arises in the study of 5d N=1 BPS states. Geometric engine
ering connects 5d N=1 BPS spectra to enumerative invariants of certain Cal
abi-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 perspec
tive on this framework\, which elucidates the geometric meaning of the inv
ariants computed by networks\, in terms of elementary data of A-branes in
the mirror geometry\, recovering an old conjecture of Joyce.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anja Butter (ITP in Heidelberg)
DTSTART:20220503T183000Z
DTEND:20220503T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/40
DESCRIPTION:Title: Normalizing Flows for LHC Theory\nby Anja Butter (ITP in Heidelb
erg) as part of NHETC Seminar\n\n\nAbstract\nOver the next years\, measure
ments at the LHC and the HL-LHC will provide us with a wealth of new data.
The best hope to answer fundamental questions\, like the nature of dark m
atter\, is to adopt big data techniques in simulations and analyses to ext
ract all 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 matc
h the experimental accuracy. Innovative ML techniques like generative mode
ls can help us overcome limitations from the high dimensionality of the ph
ase space. Such networks can be employed to directly simulate events or to
support first principle calculations like multi-loop amplitudes. Since ne
ural networks can be inverted\, they open new avenues in LHC analyses.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dalimil Mazac (IAS)
DTSTART:20220208T193000Z
DTEND:20220208T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/41
DESCRIPTION:Title: Automorphic Spectra and the Conformal Bootstrap\nby Dalimil Maza
c (IAS) as part of NHETC Seminar\n\n\nAbstract\nI will explain that the sp
ectral geometry of hyperbolic manifolds provides a remarkably faithful mod
el of the modern conformal bootstrap. In particular\, to each hyperbolic D
-manifold\, one can associate a Hilbert space of local operators\, which i
s a unitary representation of a conformal group. The local operators live
in an emergent (D-1)-dimensional spacetime. The scaling dimensions of the
operators are related to the eigenvalues of the Laplacian on the manifold.
The operators satisfy an operator product expansion. Finally\, one can de
fine their correlation functions and derive bootstrap equations constraini
ng the spectrum. As an application\, I will use conformal bootstrap techni
ques to derive upper bounds on the lowest positive eigenvalue of the Lapla
cian on closed hyperbolic surfaces and 2-orbifolds. In a number of notable
cases\, the bounds are nearly saturated by known surfaces and orbifolds.
For instance\, the bound on all genus-2 surfaces is λ1≤3.8388976481\, w
hile the Bolza surface has λ1≈3.838887258. The talk will be based on ht
tps://arxiv.org/abs/2111.12716\, which is joint work with P. Kravchuk and
S. Pal.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Peizhi Du (Stony Brook University)
DTSTART:20220315T183000Z
DTEND:20220315T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/42
DESCRIPTION:Title: New backgrounds and new ideas for sub-GeV dark matter direct detecti
on\nby Peizhi Du (Stony Brook University) as part of NHETC Seminar\n\n
\nAbstract\nProbing sub-GeV dark matter requires designing low threshold d
etectors and understanding backgrounds. In this talk I will address these
two issues. First\, we point out several unexplored low-energy backgrounds
in sub-GeV dark matter searches\, which arise from high-energy particles
of cosmic or radioactive origin that interact with detector materials. In
this talk\, I will focus on Cherenkov radiation and luminescence from elec
tron-hole pair recombination. We demonstrate that these processes provide
plausible explanations of the observed events at SENSEI and SuperCDMS HVeV
. Second\, we propose a new idea of probing light dark matter using doped
semiconductors. Dopants in semiconductors form energy levels that are tens
of meV below the conduction band or above the valence band. These materia
ls can be new detector targets for dark matter scattering with a threshold
of tens of meV\, which can probe dark matter masses down to tens of keV.\
n
LOCATION:https://stable.researchseminars.org/talk/nhetc/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Prasanth Shyamsundar (Fermilab)
DTSTART:20220517T183000Z
DTEND:20220517T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/43
DESCRIPTION:Title: Constructing sensitive and robust collider observables with machine
learning\nby Prasanth Shyamsundar (Fermilab) as part of NHETC Seminar\
n\n\nAbstract\nI will discuss some concluded and ongoing work on construct
ing\, using machine learning\, sensitive low-dimensional variables for use
in collider data analyses. I will also briefly discuss the robustness off
ered by the technique against unknown and unquantified errors in the simul
ation models.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sameer Murthy (King's College London)
DTSTART:20220920T183000Z
DTEND:20220920T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/44
DESCRIPTION:Title: Giant gravitons in gauge theory\nby Sameer Murthy (King's Colleg
e London) as part of NHETC Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anna Golubeva (MIT)
DTSTART:20220927T183000Z
DTEND:20220927T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/45
DESCRIPTION:Title: On the fundamental role of sparsity in machine learning\nby Anna
Golubeva (MIT) as part of NHETC Seminar\n\n\nAbstract\nSparsity and neura
l-network pruning have become indispensable tools in applied machine learn
ing to alleviate the computational demands of ever larger models. While th
e number of empirical works in this field has exploded in recent years\, b
ringing out a variety of pruning techniques\, finding sparse solutions at
initialization 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 and present some of our recent work combining theoretical and experi
mental approaches to tackle them.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ben Lillard (University of Oregon)
DTSTART:20221004T183000Z
DTEND:20221004T193000Z
DTSTAMP:20260404T111008Z
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://stable.researchseminars.org/talk/nhetc/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Clay Cordova (University of Chicago)
DTSTART:20221011T183000Z
DTEND:20221011T193000Z
DTSTAMP:20260404T111008Z
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://stable.researchseminars.org/talk/nhetc/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eliezer Rabinovici (CERN)
DTSTART:20221018T183000Z
DTEND:20221018T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/48
DESCRIPTION:Title: Persistent Spontaneous Symmetry Breaking at High Temperatures\nb
y Eliezer Rabinovici (CERN) as part of NHETC Seminar\n\n\nAbstract\nI will
describe the results of a series of works in which we have found systems
for which Spontaneous Symmetry Breaking(SSB) persists to very high tempera
tures. \nThe systems involve Conformal Field Theories of scalars in fracti
onal dimensions 3Factorization and Global symmetries in holography\nby Lorenzo Di
Pietro (UNITS) as part of NHETC Seminar\n\n\nAbstract\nBased on 2203.0953
7. In the context of toy models of holography arising from 3d Chern-Simons
theory\, I will describe an approach in which\, rather than summing over
bulk geometries\, one gauges a one-form global symmetry of the bulk theory
. This ensures that the bulk theory has no global symmetries\, and it make
s the partition function on spacetimes with boundaries coincide with that
of a modular-invariant 2d CFT on the boundary. In particular\, on wormhole
geometries one finds a factorized answer for the partition function.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Kutasov (University of Chicago)
DTSTART:20221101T183000Z
DTEND:20221101T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/50
DESCRIPTION:Title: Small Black Holes in String Theory\nby David Kutasov (University
of Chicago) as part of NHETC Seminar\n\n\nAbstract\nI will describe some
recent work on Euclidean Schwarzschild black holes in d+1 dimensional flat
spacetime\, in the limit where their Hawking temperature approaches the H
agedorn temperature. This leads to new conformal field theories\, enhanced
symmetry at the Hagedorn temperature\, and relations to earlier work on b
lack holes at large d. If there is time\, I will also discuss an open stri
ng analog of this problem\, that exhibits similar phenomena.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthew Bullimore (Durham University)
DTSTART:20221108T193000Z
DTEND:20221108T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/51
DESCRIPTION:Title: Non-invertible symmetry and higher representation theory\nby Mat
thew Bullimore (Durham University) as part of NHETC Seminar\n\n\nAbstract\
nThe past year has seen an explosion in constructions of non-invertible sy
mmetries in quantum field theories in dimension greater than two\, such as
gauging discrete symmetries with mixed ’t Hooft anomalies\, gauging non
-normal subgroups of discrete symmetries\, higher gauging and condensation
s\, and duality defects. I’ll present a common framework for such constr
uctions based on higher representation theory\, which describes higher dim
ensional analogues of topological Wilson lines. Based on joint work with T
homas Bartsch\, Andrea Ferrari and Jamie Pearson.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shu-Heng Shao (Stony Brook University)
DTSTART:20221115T193000Z
DTEND:20221115T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/52
DESCRIPTION:Title: Non-invertible Symmetries in Nature\nby Shu-Heng Shao (Stony Bro
ok University) as part of NHETC Seminar\n\n\nAbstract\nI will talk about n
on-invertible global symmetries in QED and QCD\, and how the neutral pion
decay rate can be determined from matching this new global symmetry. I wil
l then discuss a non-invertible 1-form symmetry from the anomalous Gauss l
aw in axion-Maxwell theory.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joshua Foster (MIT)
DTSTART:20221122T193000Z
DTEND:20221122T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/53
DESCRIPTION:Title: Lumped Element Axion Detection at All Frequencies\nby Joshua Fos
ter (MIT) as part of NHETC Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Keisuke Harigaya (University of Chicago)
DTSTART:20221129T193000Z
DTEND:20221129T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/54
DESCRIPTION:Title: Cosmology of Axion Rotation\nby Keisuke Harigaya (University of
Chicago) as part of NHETC Seminar\n\n\nAbstract\nWe will introduce new cos
mological dynamics of the QCD axion\, where the axion field rotates in fie
ld space. Axion dark matter may be produced from the kinetic energy of the
rotation and the required axion decay constant is much below the predicti
on of the conventional evolutions. The angular momentum of the rotation is
transferred into baryon asymmetry through baryon number violating interac
tions. We discuss the electroweak sphaleron process and some beyond-standa
rd model processes and predictions on the parameters of each theory.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Isabel Garcia Garcia (University of California - Santa Barbara)
DTSTART:20221206T193000Z
DTEND:20221206T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/55
DESCRIPTION:Title: The Rocket Science of Bubble Walls\nby Isabel Garcia Garcia (Uni
versity of California - Santa Barbara) as part of NHETC Seminar\n\n\nAbstr
act\nCosmological phase transitions that proceed via nucleation of bubbles
are a well-motivated possibility both in minimal extensions of the Standa
rd Model as well as in more general hidden sectors with their own dynamics
. Such an event produces a stochastic background of gravitational radiatio
n that could be observed by current and future observatories. That said\,
our ability to extract any detailed information about the underlying dynam
ics from such an observation is extremely limited\, and highlights the nec
essity of (i) better understanding the dynamics of bubble walls in the ear
ly Universe\, given their impact on the high-frequency shape of the signal
\, and (ii) exploring complementary probes of an observable gravitational
wave background.\n\nIn this talk\, I will discuss the dynamics of expandin
g vacuum bubbles in the presence of massive vectors (a.k.a. dark photons)
that gain mass across the interface -- with a special focus on the well-mo
tivated benchmark where the dark photons furnish the dark matter. I will a
rgue the existence of a transient kinematic regime during which the wall b
ehaves as an (imperfect) mirror of longitudinal -- but not transverse -- m
odes. Most notably\, this leads to a new source of pressure on the expandi
ng interface that can prevent the accelerated expansion of the bubble wall
s. Instead of accelerating the interface\, the difference in vacuum energy
density across the wall goes into making a fraction of the dark photons r
elativistic\, turning them into dark radiation. The corresponding value of
\\Delta N_eff is determined by the strength of the phase transition and t
he epoch at which the transition takes place. Current \\Delta N_eff constr
aints can rule out phase transitions with strength \\alpha \\simeq 0.1\, w
hereas CMB S-4 measurements will probe scenarios down to \\alpha = 0.01 fo
r all relevant frequencies.\n\nThis talk is based on arXiv:2212.xxxxx in c
ollaboration with Giacomo Koszegi and Rudin Petrossian-Byrne.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikita Nekrasov (Stony Brook University)
DTSTART:20220929T180000Z
DTEND:20220929T190000Z
DTSTAMP:20260404T111008Z
UID:nhetc/56
DESCRIPTION:Title: One flew over the QQ-nest\nby Nikita Nekrasov (Stony Brook Unive
rsity) as part of NHETC Seminar\n\n\nAbstract\nI will discuss the recent p
rogress 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 surf
ace defects. According to the BPS/CFT dictionary their expectation values
are given by the conformal blocks of some (analytically continued) CFT\, a
nd\, 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}-system and the Lax operators\, filling some gaps in the 30 year cycle o
f ideas connecting supersymmetry and integrability.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Netta Engelhardt (MIT)
DTSTART:20221110T190000Z
DTEND:20221110T200000Z
DTSTAMP:20260404T111008Z
UID:nhetc/57
DESCRIPTION:Title: Non-Isometric Codes\, Complexity\, and the Black Hole Information Pa
radox\nby Netta Engelhardt (MIT) as part of NHETC Seminar\n\n\nAbstrac
t\nThis talk focuses on recent progress on the role of computational compl
exity in the black hole information paradox. I will describe quantum code
models that settle the tension between two conflicting calculations of the
entropy of Hawking radiation within semiclassical gravity: the standard
“Hawking” calculation and the quantum extremal surface calculation. Th
e critical aspect of the construction involves a complexity bound on the v
alidity of effective field theory\, and I will discuss applications of thi
s from the geometric perspective of holography as well as computationally
bounded quantum learning.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seminar is Cancelled: Gabriel Wong (Harvard CMSA)
DTSTART:20221201T190000Z
DTEND:20221201T200000Z
DTSTAMP:20260404T111008Z
UID:nhetc/58
DESCRIPTION:Title: Seminar is Cancelled: Generalized entropy in topological string the
ory\nby Seminar is Cancelled: Gabriel Wong (Harvard CMSA) as part of
NHETC Seminar\n\n\nAbstract\nSeminar is Cancelled: The holographic entang
lement entropy formula identifies the generalized entropy of the bulk AdS
spacetime with the entanglement entropy of the boundary CFT. However the b
ulk microstate interpretation of the generalized entropy remains poorly un
derstood. Progress along this direction requires a definition of Hilbert s
pace factorization and entanglement entropy in the bulk closed string theo
ry. As a toy model for AdS/CFT\, we study the entanglement entropy of cl
osed strings in the topological A model\, which enjoys a gauge-string dual
ity. We define a notion of generalized entropy for closed strings on the
resolved conifold using the replica trick. As in AdS/CFT\, we find this
is dual to (defect) entanglement entropy in the dual Chern Simons gauge t
heory. Our main result is a bulk microstate interpretation of the genera
lized entropy for closed strings as the entanglement entropy of open strin
gs ending on ``entanglement branes" . These branes are interpreted as
entanglement edge modes\, which transform under a quantum group symmetry.
We relate these entanglement branes to the D branes of the A model topolo
gical string.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sunil Mukhi (IISER Pune)
DTSTART:20221208T190000Z
DTEND:20221208T200000Z
DTSTAMP:20260404T111008Z
UID:nhetc/59
DESCRIPTION:Title: Classification of Unitary RCFTs with Two Primaries and c < 25\nb
y Sunil Mukhi (IISER Pune) as part of NHETC Seminar\n\n\nAbstract\nI will
present a classification of all unitary\, rational\nconformal field theori
es with two primaries\, central charge c < 25\,\nand arbitrary Wronskian i
ndex. (Work in collaboration with Brandon\nRayhaun\, arXiv: 2208.05486).
These are shown to be either certain\nlevel-1 WZW models or cosets of mero
morphic theories by such models.\nBy leveraging the existing classificatio
n of meromorphic CFTs of\ncentral charge c ≤ 24\, all the relevant cose
ts are enumerated and\ntheir characters computed. This leads to 123 theori
es\, most of which\nare new. It will be emphasised that this is a classifi
cation of RCFTs\nand not just consistent characters.This work makes use of
early\nresults in the classification of RCFT using modular linear\ndiffer
ential equations and cosets\, the relevant background will be\nreviewed.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Petr Hořava (UC Berkeley)
DTSTART:20221213T193000Z
DTEND:20221213T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/60
DESCRIPTION:Title: Topological Quantum Gravity of the Ricci Flow\nby Petr Hořava (
UC Berkeley) as part of NHETC Seminar\n\n\nAbstract\nUsing the techniques
of cohomological quantum field theories\, we construct a topological nonre
lativistic quantum gravity\, designed around the mathematical theory of th
e Ricci flow on Riemannian manifolds\, as used by Perelman in his proof of
the Poincare conjecture and Thurston's geometrization theorem. This quan
tum field theory brings together three\, previously not directly related a
reas: Topological field theory of the cohomological type\, nonrelativisti
c quantum gravity of the Lifshitz type\, and the mathematics of geometric
flows on manifolds. We identify the precise theory whose path integral lo
calizes to the solutions of the Perelman's version of the Ricci flow equat
ions\, and identify various features of Perelman's construction in the phy
sics language\, such as Perelman's entropy functional (which plays the rol
e of our superpotential)\, Perelman's dilaton field (which maps to the lap
se function of nonrelativistic gravity)\, and others. With this embedding
of Perelman's Ricci flow to topological quantum gravity\, many intriguing
results about the structure of the flow accumulated on the mathematical s
ide in the past two decades can now be imported into the physical picture
in the path integral formulation of quantum gravity.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ingo Runkel (Universität Hamburg)
DTSTART:20221220T193000Z
DTEND:20221220T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/61
DESCRIPTION:Title: Topological symmetries and their gaugings in 2dCFT and 3dTFT\nby
Ingo Runkel (Universität Hamburg) as part of NHETC Seminar\n\n\nAbstract
\nThe study of topological defects in quantum field theory as seen a wealt
h of activity recently leading to many interesting insights\, for example
the explicit realization of non-invertible topological defects in higher d
imensional QFTs via the gauging of higher form symmetries\, or the descrip
tion of the higher algebraic structures inherent in these topological defe
cts. \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 already. I would like to exhibit some of the properties of topologica
l defects in two-dimensional conformal field theory and in three-dimension
al topological field theory\, and show some of the structural insights int
o 2dCFT and 3dTFT one can gain with the help of defects. In this way\, the
well-understood low-dimensional case might serves as a source of ideas an
d as a test-case for higher dimensional constructions.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Tong (University of Cambridge)
DTSTART:20230124T193000Z
DTEND:20230124T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/62
DESCRIPTION:Title: A Chern-Simons Theory for the North Atlantic Ocean\nby David Ton
g (University of Cambridge) as part of NHETC Seminar\n\n\nAbstract\nIn som
e ways the ocean acts like a topological insulator. There are chiral edge
modes\, localised at the coast\, that go clockwise in the Northern hemisph
ere and anti-clockwise in the Southern hemisphere. I’ll describe these p
roperties and explain how they can be understood in terms of something mor
e familiar 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-Cher
n-Simons theory.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/62/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nathan Seiberg (Institute for Advanced Study)
DTSTART:20230131T193000Z
DTEND:20230131T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/63
DESCRIPTION:Title: Symmetries and Anomalies in the Continuum and on the Lattice\nby
Nathan Seiberg (Institute for Advanced Study) as part of NHETC Seminar\n\
n\nAbstract\nBased on joint work with Meng Cheng (arXiv:2211.12543)\, we w
ill discuss some aspects of global symmetries and their ‘t Hooft anomali
es.\n\nWe will define a notion of an emanant global symmetry. It is not a
symmetry of the UV theory\, but unlike emergent (accidental) symmetries\,
it is not violated by any relevant or irrelevant operators in the IR theor
y.\n\nWe will present lattice models with anomalous internal symmetries an
d see how the anomalies are diagnosed on the lattice using topological def
ects.\n\nWe will also discuss lattice models with anomalous lattice transl
ation and relate them to an anomalous emanant symmetry in the IR theory. T
his will connect our discussion to the well-known Lieb-Schultz-Mattis theo
rem and to filling constraints like Luttinger theorem.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Johanna Erdmenger (Julius Maximilian University Würzburg)
DTSTART:20230425T183000Z
DTEND:20230425T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/64
DESCRIPTION:Title: Discrete Holography\nby Johanna Erdmenger (Julius Maximilian Uni
versity Würzburg) as part of NHETC Seminar\n\n\nAbstract\nI will review r
ecent progress towards establishing a holographic duality for discrete spa
ces involving a regular tiling of hyperbolic space. In particular\, I will
present a recent example where an aperiodic XXZ spin chain is obtained na
turally by extrapolating the bulk tiling to its boundary. The properties o
f this model are studied using RG techniques\, which provide a tensor netw
ork construction for its ground state. We calculate and compare the entang
lement entropy both at the boundary and in the bulk. I will comment on the
symmetries of the construction and on the next steps towards obtaining a
full dynamical duality of discrete systems. In particular\, this may be us
eful for 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://stable.researchseminars.org/talk/nhetc/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fiona Burnell (University of Minnesota)
DTSTART:20230523T183000Z
DTEND:20230523T193000Z
DTSTAMP:20260404T111008Z
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\nAbs
tract\nThe notion that symmetry in a d-dimensional QFT is naturally descri
bed by placing this QFT at the boundary of a d+1 dimensional TQFT has been
very powerful in understanding generalized symmetry actions\, particularl
y for non-invertible symmetries. I discuss a concrete family of models i
n 2 spatial dimensions\, which can be viewed on the one hand as Hamiltonia
n models describing bulk topological orders\, and on the other hand (when
the bulk is in its ground state) as bulk TQFT’s describing a symmetry ac
tion at the boundary. I will describe how to add additional symmetry by
“shading” and “completing” the bulk models. This leads to models
which realize interesting symmetries in an onsite manner. Specifically\,
in the bulk\, these shaded models realize symmetries that permute the any
ons in the underlying TQFT. At the boundary\, these symmetries can take
the form of generalized Kramers-Wannier dualities in the boundary spin mod
el. I will illustrate how this works in a few simple examples.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mihoko Nojiri (KEK Theory Center)
DTSTART:20230202T173000Z
DTEND:20230202T183000Z
DTSTAMP:20260404T111008Z
UID:nhetc/67
DESCRIPTION:Title: Future electron beam dump experiments\nby Mihoko Nojiri (KEK The
ory Center) as part of NHETC Seminar\n\n\nAbstract\nA beam dump experiment
can be seamlessly added to the proposed International Linear Collider (IL
C) program because the high-energy electron beam should be dumped after th
e collision point. The ILC beam dump experiment will provide an excellent
opportunity to search for new long-lived particles(LLP). An LPP couple to
a photon\, such as axion-like particles\, can be searched there. Furthermo
re\, the photon and electron in EM shower hit nuclei and produce hadrons.
As a motivated physics case\, we study the projected sensitivity of heavy
neutral leptons at the ILC beam dump experiment. The study shows\,somewhat
counter-intuitively\, that the reach would be significantly extended in m
ass and coupling\, even compared with the other proposed searches. I als
o introduce proposed ALP studies using KEK linac\; currently\, test beam s
tudies are starting.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Malte Buschmann (Princeton University)
DTSTART:20230207T193000Z
DTEND:20230207T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/68
DESCRIPTION:Title: The post-inflationary axion\nby Malte Buschmann (Princeton Unive
rsity) as part of NHETC Seminar\n\n\nAbstract\nThe axion is a hypothetical
particle that solves the strong CP problem of quantum chromodynamics (QCD
) while simultaneously being an excellent dark matter candidate. If the ax
ion is generated after inflation\, many unique objects arise from the theo
ry\, from axion strings and domain walls to oscillons\, miniclusters\, and
axion stars. The result is many potentially observable signatures\, wheth
er in the CMB\, the gravitational wave background or in neutron star data.
More importantly\, this scenario is entirely deterministic\, allowing pre
cise predictions through numerical simulations. In this talk\, I will go t
hrough the cosmological history of such a post-inflationary axion to put t
he various phenomena into context and highlight the remaining open questio
ns.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edward Witten (Institute for Advanced Study)
DTSTART:20230221T193000Z
DTEND:20230221T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/69
DESCRIPTION:Title: The Timelike Tube Theorem\nby Edward Witten (Institute for Advan
ced Study) as part of NHETC Seminar\n\n\nAbstract\nI will explain the idea
s involved 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 algebra of quantum fields in a spacetime region that is causally acc
essible to the observer. The earliest version was proved by Borchers and A
raki in the 1960's.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/69/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Manuel Szewc (University of Cincinnati)
DTSTART:20230307T193000Z
DTEND:20230307T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/71
DESCRIPTION:Title: Null Hypothesis Test for Anomaly Detection\nby Manuel Szewc (Uni
versity of Cincinnati) as part of NHETC Seminar\n\n\nAbstract\nIn this tal
k we present a hypothesis test designed to exclude the background-only hyp
othesis for Anomaly detection searchs. Extending Classification Without La
bels\, we show that by testing for statistical independence of the two dis
criminating dataset regions\, we are able exclude the background-only hypo
thesis without relying on fixed anomaly score cuts or extrapolations of ba
ckground estimates between regions. The method relies on the assumption of
conditional independence of anomaly score features and dataset regions\,
which can be ensured using existing decorrelation techniques. As a benchma
rk example\, we consider the LHC Olympics dataset where we show that mutua
l information represents a suitable test for statistical independence and
our method exhibits excellent and robust performance at different signal f
ractions even in presence of realistic feature correlations.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/71/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gleb Kotousov (Leibniz University Hannover)
DTSTART:20230309T190000Z
DTEND:20230309T200000Z
DTSTAMP:20260404T111008Z
UID:nhetc/72
DESCRIPTION:Title: 2D black hole sigma models from an integrable spin chain\nby Gle
b Kotousov (Leibniz University Hannover) as part of NHETC Seminar\n\n\nAbs
tract\nThe staggered six-vertex model is a 1D critical integrable spin cha
in that exhibits a variety of interesting universal behaviour. This includ
es a regime where the spectrum of critical exponents contains a continuous
component and matches that of the Euclidean version of the 2D black hole
non-linear sigma model. In this talk the relation between the scaling limi
t of the vertex model and the Euclidean/Lorentzian black hole sigma models
is discussed. Some new results on the density of states of the continuous
spectrum for the Euclidean black hole CFT are presented\, which were obta
ined via an analysis of the lattice system. The talk is largely based on t
he work 2010.10603.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/72/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kevin Croker (University of Hawaii)
DTSTART:20230314T183000Z
DTEND:20230314T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/73
DESCRIPTION:by Kevin Croker (University of Hawaii) as part of NHETC Semina
r\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/73/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Dunsky (NYU)
DTSTART:20230321T183000Z
DTEND:20230321T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/74
DESCRIPTION:Title: A Heavy QCD Axion and the Mirror World\nby David Dunsky (NYU) as
part of NHETC Seminar\n\n\nAbstract\nIn this talk\, I will discuss the mi
rror world with dark matter arising from the thermal freeze-out of the lig
htest\, stable mirror particle -- the mirror electron. The dark matter abu
ndance is achieved for mirror electrons of mass 225 GeV\, fixing the mirro
r electroweak scale near 10^8 GeV. This highly predictive scenario is real
ized by an axion that acts as a portal between the two sectors through its
coupling to the QCD and mirror QCD sectors. The axion is more massive tha
n the standard QCD axion due to additional contributions from mirror stron
g dynamics. 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 transferred into the Standard Model sector via the axion portal\, which
alleviates overproduction of dark radiation from mirror glueball decays.
I will discuss four signals from this model: (1) primordial gravitational
waves from the first-order mirror QCD phase transition occurring at a temp
erature near 35 GeV\, (2) effects on large-scale structure from dark matte
r self-interactions from mirror QED\, (3) dark radiation affecting the cos
mic microwave background\, and (4) the rare kaon decay\, (kaon -> pion +ax
ion). The first two signals do not depend on any fundamental free paramete
rs of the theory while the latter two depend on a single free parameter\,
the axion decay constant.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/74/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Annika Peter (Harvard)
DTSTART:20230404T183000Z
DTEND:20230404T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/75
DESCRIPTION:by Annika Peter (Harvard) as part of NHETC Seminar\n\nAbstract
: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/75/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seth Koren (Chicago)
DTSTART:20230502T183000Z
DTEND:20230502T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/76
DESCRIPTION:Title: Putting Generalized Symmetries to Work for Particle Physics\nby
Seth Koren (Chicago) as part of NHETC Seminar\n\n\nAbstract\nOver the past
decade\, field theorists have developed a novel framework for thinking ab
out global symmetries which has enormously generalized our understanding t
hereof. Quite recently\, my collaborators and I have established positivel
y that past being a useful formal tool\, such generalized symmetries are i
ndeed present in models that we care about as particle physicists---and fu
rthermore understanding them can lead to new insights into these models. A
s a first example\, the Standard Model itself has a 'higher-group' symmetr
y intertwining flavor and hypercharge\, and I will discuss how this symmet
ry controls the structure of unification. Going Beyond\, I will show that
the identification of a 'non-invertible' symmetry of Z' models of L_µ - L
_τ reveals the existence of simple UV completions thereof where the scale
of neutrino masses is exponentially suppressed from that of charged lepto
ns.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/76/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mariel Pettee (Lawrence Berkeley National Laboratory / Flatiron In
stitute Center for Computational Astrophysics)
DTSTART:20230511T163000Z
DTEND:20230511T183000Z
DTSTAMP:20260404T111008Z
UID:nhetc/77
DESCRIPTION:Title: Weakly-Supervised Anomaly Detection in the Milky Way\nby Mariel
Pettee (Lawrence Berkeley National Laboratory / Flatiron Institute Center
for Computational Astrophysics) as part of NHETC Seminar\n\n\nAbstract\nCl
assification Without Labels (CWoLa) is a weakly-supervised anomaly detecti
on technique that leverages neural networks to identify cold stellar strea
ms within the more than one billion Milky Way stars observed by the Gaia s
atellite. The CWoLa methodology operates without the use of labeled stream
s or knowledge of astrophysical principles. Instead\, it uses a classifier
to distinguish between mixed samples for which the proportions of signal
and background samples are unknown. This computationally lightweight strat
egy is able to detect both simulated streams and the known stream GD-1 in
data. Originally designed for high-energy collider physics\, this techniqu
e may have broad applicability within astrophysics as well as other domain
s interested in identifying localized anomalies.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/77/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan Heckman (University of Pennsylvania)
DTSTART:20230228T193000Z
DTEND:20230228T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/78
DESCRIPTION:Title: IIB Determined\nby Jonathan Heckman (University of Pennsylvania)
as part of NHETC Seminar\n\n\nAbstract\nWe use the Swampland Cobordism Co
njecture recently proposed by McNamara and Vafa to study the spectrum of o
bjects in type IIB string theory. A famous feature of type IIB string theo
ry (as well as many quantum systems) is that it enjoys a non-abelian duali
ty group. By computing the relevant cobordism groups\, we show that the co
bordism conjecture successfully reconstructs many known supersymmetric obj
ects\, and also predicts the existence of a new non-supersymmetric "reflec
tion 7-brane\," the properties of which we describe. Based on joint work w
ith Debray\, Dierigl\, Montero and Torres.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/78/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lina Necib (MIT)
DTSTART:20230905T183000Z
DTEND:20230905T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/79
DESCRIPTION:Title: (Machine) Learning of Dark Matter\nby Lina Necib (MIT) as part o
f NHETC Seminar\n\n\nAbstract\nIn this talk\, I explore the impact of stel
lar kinematics on understanding the particle nature of Dark Matter\, overv
iewing the correlations between stellar and Dark Matter phase space distri
butions in three separate locations: the solar neighborhood\, the Galactic
center\, and dwarf galaxies. I will focus on the use of machine learning
techniques applied to data from the Gaia mission to disentangle the local
kinematics substructures\, and the use of simulations to study the correla
tions between stars and Dark Matter. I will end by relating these empirica
l measurements to Dark Matter detection experiments.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/79/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Katherine Fraser (Harvard)
DTSTART:20230418T183000Z
DTEND:20230418T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/80
DESCRIPTION:by Katherine Fraser (Harvard) as part of NHETC Seminar\n\nAbst
ract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/80/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stefano Negro (NYU)
DTSTART:20230328T183000Z
DTEND:20230328T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/81
DESCRIPTION:Title: The relevance of being irrelevant\nby Stefano Negro (NYU) as par
t of NHETC Seminar\n\n\nAbstract\nIn the last few years\, 2-dimensional Qu
antum Field Theories deformed by irrelevant operators have been receiving
a steadily growing amount of attention from the Theoretical Physics commun
ity. The main reason for this interest lies in the unexpected amount of co
ntrol that it is possible to exert on the high-energy properties of a vast
family of these deformations. These\, often referred to as “solvable ir
relevant deformations”\, in spite of being by standard arguments non-ren
ormalisable\, 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 re
markable: the finite-size density of states grows exponentially at high en
ergies\, in a Hagedorn fashion reminiscent of String Theories. These defor
med theories are not compatible with Wilson’s paradigm of local QFTs and
cannot be considered conventional UV-complete theories. However\, thanks
to their robust features\, they represent a sensible extension of the Wils
onian notion of a local QFT.\n\nI will recall the main features of the TTb
ar deformations\, the poster child of solvable irrelevant deformations\, i
n an introductory manner. If time permits I will then describe the more re
cent developments for a vast class of irrelevant deformations of 2D Integr
able QFTs\, paying particular attention to their interpretation as factori
sed scattering theories. This perspective reveals the importance of these
theories in the task undertaken by the Bootstrap community of mapping out
the space of consistent scattering matrices.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/81/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Banks (Rutgers)
DTSTART:20230323T183000Z
DTEND:20230323T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/82
DESCRIPTION:Title: The Density Matrix of a Causal Diamond\nby Thomas Banks (Rutgers
) as part 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 causal diamond in models of quantum gravity is finite dimensional an
d that the modular Hamiltonian of the "empty diamond" state has an expecta
tion value and fluctuations determined by geometrical properties of the di
amond. These universal formulae depend on a view of Einstein's equations
as the hydrodynamic equations of the area law for diamond entropy\, which
means that they are valid beyond any "semi-classical" approximation. A mo
del of quantum gravity consists of finding a quantum system whose hydrodyn
amics is consistent with a given solution of Einstein's equations. I will
quickly review many papers and attendees are encouraged to read them befo
re the talk. (List will follow). Among the many implications of these pa
pers is that quantum field theory cannot account for most of the entropy i
n a causal diamond\, and that the cosmological constant should not be thou
ght 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:10.11
03/PhysRevLett.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/Phys
RevD.101.126010[arXiv:1911.05778 [hep-th]].\n\n 3. N. Blinov and P. Dra
per\, Phys. Rev. D 104\, no.7\, 076024 (2021) doi:10.1103/PhysRevD.104.076
024[arXiv: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) do
i:10.1103/PhysRevLett.71.666[arXiv:hep-th/9303048 [hep-th]].\n\n 6. C.
G. Callan\, Jr. and F. Wilczek\, Phys. Lett. B 333\, 55-61 (1994) doi:10.1
016/0370-2693(94)91007-3 [arXiv:hep-th/9401072 [hep-th]].\n\n 7. L. Sus
skind and J. Uglum\, Phys. Rev. D 50\, 2700-2711 (1994) doi:10.1103/PhysRe
vD.50.2700[arXiv:hep-th/9401070 [hep-th]].\n\n 8. T. Jacobson\, [arXiv:
gr-qc/9404039 [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:10.10
88/0264-9381/17/5/309[arXiv:hep-th/9911002 [hep-th]]. ETC.\n\n 12. H. L
. Verlinde and E. P. Verlinde\, Nucl. Phys. B 371\, 246-268 (1992) doi:10.
1016/0550-3213(92)90236-5 [arXiv:hep-th/9110017 [hep-th]].\n\n 13. S. C
arlip\, Phys. Rev. Lett. 82\, 2828-2831 (1999) doi:10.1103/PhysRevLett.82.
2828[arXiv:hep-th/9812013 [hep-th]]. ETC.\n\n 14. S. N. Solodukhin\, Ph
ys. Lett. B 454\, 213-222 (1999) doi:10.1016/S0370-2693(99)00398-6[arXiv:h
ep-th/9812056 [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://stable.researchseminars.org/talk/nhetc/82/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Banks (Rutgers)
DTSTART:20230330T183000Z
DTEND:20230330T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/83
DESCRIPTION:Title: The Density Matrix of a Causal Diamond\nby Thomas Banks (Rutgers
) as part 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 causal diamond in models of quantum gravity is finite dimensional an
d that the modular Hamiltonian of the "empty diamond" state has an expecta
tion value and fluctuations determined by geometrical properties of the di
amond. These universal formulae depend on a view of Einstein's equations
as the hydrodynamic equations of the area law for diamond entropy\, which
means that they are valid beyond any "semi-classical" approximation. A mo
del of quantum gravity consists of finding a quantum system whose hydrodyn
amics is consistent with a given solution of Einstein's equations. I will
quickly review many papers and attendees are encouraged to read them befo
re the talk. (List will follow). Among the many implications of these pa
pers is that quantum field theory cannot account for most of the entropy i
n a causal diamond\, and that the cosmological constant should not be thou
ght 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:10.11
03/PhysRevLett.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/Phys
RevD.101.126010[arXiv:1911.05778 [hep-th]].\n\n 3. N. Blinov and P. Dra
per\, Phys. Rev. D 104\, no.7\, 076024 (2021) doi:10.1103/PhysRevD.104.076
024[arXiv: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) do
i:10.1103/PhysRevLett.71.666[arXiv:hep-th/9303048 [hep-th]].\n\n 6. C.
G. Callan\, Jr. and F. Wilczek\, Phys. Lett. B 333\, 55-61 (1994) doi:10.1
016/0370-2693(94)91007-3 [arXiv:hep-th/9401072 [hep-th]].\n\n 7. L. Sus
skind and J. Uglum\, Phys. Rev. D 50\, 2700-2711 (1994) doi:10.1103/PhysRe
vD.50.2700[arXiv:hep-th/9401070 [hep-th]].\n\n 8. T. Jacobson\, [arXiv:
gr-qc/9404039 [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:10.10
88/0264-9381/17/5/309[arXiv:hep-th/9911002 [hep-th]]. ETC.\n\n 12. H. L
. Verlinde and E. P. Verlinde\, Nucl. Phys. B 371\, 246-268 (1992) doi:10.
1016/0550-3213(92)90236-5 [arXiv:hep-th/9110017 [hep-th]].\n\n 13. S. C
arlip\, Phys. Rev. Lett. 82\, 2828-2831 (1999) doi:10.1103/PhysRevLett.82.
2828[arXiv:hep-th/9812013 [hep-th]]. ETC.\n\n 14. S. N. Solodukhin\, Ph
ys. Lett. B 454\, 213-222 (1999) doi:10.1016/S0370-2693(99)00398-6[arXiv:h
ep-th/9812056 [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://stable.researchseminars.org/talk/nhetc/83/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gabriel Wong (Harvard CMSA)
DTSTART:20230504T180000Z
DTEND:20230504T190000Z
DTSTAMP:20260404T111008Z
UID:nhetc/84
DESCRIPTION:Title: Generalized entropy in topological string theory\nby Gabriel Won
g (Harvard CMSA) as part of NHETC Seminar\n\n\nAbstract\nThe holographic e
ntanglement entropy formula identifies the generalized entropy of the bulk
AdS spacetime with the entanglement entropy of the boundary CFT. However
the bulk microstate interpretation of the generalized entropy remains poor
ly understood. Progress along this direction requires a definition of Hil
bert space factorization and entanglement entropy in the bulk closed strin
g theory. As a toy model for AdS/CFT\, we study the entanglement entropy
of closed strings in the topological A model\, which enjoys a gauge-string
duality. We define a notion of generalized entropy for closed strings on
the resolved conifold using the replica trick. As in AdS/CFT\, we find
this is dual to (defect) entanglement entropy in the dual Chern Simons gau
ge theory. Our main result is a bulk microstate interpretation of the ge
neralized entropy for closed strings as the entanglement entropy of open s
trings ending on ``entanglement branes" . These branes are interpreted as
entanglement edge modes\, which transform under a quantum group symmetry.
We relate these entanglement branes to the Dbranes of the A model topolog
ical string.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/84/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Banks (Rutgers)
DTSTART:20230427T183000Z
DTEND:20230427T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/85
DESCRIPTION:Title: The Density Matrix Of A Causal Diamond\nby Thomas Banks (Rutgers
) as part 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 causal diamond in models of quantum gravity is finite dimensional an
d that the modular Hamiltonian of the "empty diamond" state has an expecta
tion value and fluctuations determined by geometrical properties of the di
amond. These universal formulae depend on a view of Einstein's equations
as the hydrodynamic equations of the area law for diamond entropy\, which
means that they are valid beyond any "semi-classical" approximation. A mo
del of quantum gravity consists of finding a quantum system whose hydrodyn
amics is consistent with a given solution of Einstein's equations. I will
quickly review many papers and attendees are encouraged to read them befo
re the talk. (List will follow). Among the many implications of these pa
pers is that quantum field theory cannot account for most of the entropy i
n a causal diamond\, and that the cosmological constant should not be thou
ght 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:10.11
03/PhysRevLett.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/Phys
RevD.101.126010[arXiv:1911.05778 [hep-th]].\n\n 3. N. Blinov and P. Dra
per\, Phys. Rev. D 104\, no.7\, 076024 (2021) doi:10.1103/PhysRevD.104.076
024[arXiv: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) do
i:10.1103/PhysRevLett.71.666[arXiv:hep-th/9303048 [hep-th]].\n\n 6. C.
G. Callan\, Jr. and F. Wilczek\, Phys. Lett. B 333\, 55-61 (1994) doi:10.1
016/0370-2693(94)91007-3 [arXiv:hep-th/9401072 [hep-th]].\n\n 7. L. Sus
skind and J. Uglum\, Phys. Rev. D 50\, 2700-2711 (1994) doi:10.1103/PhysRe
vD.50.2700[arXiv:hep-th/9401070 [hep-th]].\n\n 8. T. Jacobson\, [arXiv:
gr-qc/9404039 [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:10.10
88/0264-9381/17/5/309[arXiv:hep-th/9911002 [hep-th]]. ETC.\n\n 12. H. L
. Verlinde and E. P. Verlinde\, Nucl. Phys. B 371\, 246-268 (1992) doi:10.
1016/0550-3213(92)90236-5 [arXiv:hep-th/9110017 [hep-th]].\n\n 13. S. C
arlip\, Phys. Rev. Lett. 82\, 2828-2831 (1999) doi:10.1103/PhysRevLett.82.
2828[arXiv:hep-th/9812013 [hep-th]]. ETC.\n\n 14. S. N. Solodukhin\, Ph
ys. Lett. B 454\, 213-222 (1999) doi:10.1016/S0370-2693(99)00398-6[arXiv:h
ep-th/9812056 [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://stable.researchseminars.org/talk/nhetc/85/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Banks (Rutgers)
DTSTART:20230511T183000Z
DTEND:20230511T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/86
DESCRIPTION:Title: The Density Matrix Of A Causal Diamond\nby Thomas Banks (Rutgers
) as part 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 causal diamond in models of quantum gravity is finite dimensional an
d that the modular Hamiltonian of the "empty diamond" state has an expecta
tion value and fluctuations determined by geometrical properties of the di
amond. These universal formulae depend on a view of Einstein's equations
as the hydrodynamic equations of the area law for diamond entropy\, which
means that they are valid beyond any "semi-classical" approximation. A mo
del of quantum gravity consists of finding a quantum system whose hydrodyn
amics is consistent with a given solution of Einstein's equations. I will
quickly review many papers and attendees are encouraged to read them befo
re the talk. (List will follow). Among the many implications of these pa
pers is that quantum field theory cannot account for most of the entropy i
n a causal diamond\, and that the cosmological constant should not be thou
ght 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:10.11
03/PhysRevLett.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/Phys
RevD.101.126010[arXiv:1911.05778 [hep-th]].\n\n 3. N. Blinov and P. Dra
per\, Phys. Rev. D 104\, no.7\, 076024 (2021) doi:10.1103/PhysRevD.104.076
024[arXiv: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) do
i:10.1103/PhysRevLett.71.666[arXiv:hep-th/9303048 [hep-th]].\n\n 6. C.
G. Callan\, Jr. and F. Wilczek\, Phys. Lett. B 333\, 55-61 (1994) doi:10.1
016/0370-2693(94)91007-3 [arXiv:hep-th/9401072 [hep-th]].\n\n 7. L. Sus
skind and J. Uglum\, Phys. Rev. D 50\, 2700-2711 (1994) doi:10.1103/PhysRe
vD.50.2700[arXiv:hep-th/9401070 [hep-th]].\n\n 8. T. Jacobson\, [arXiv:
gr-qc/9404039 [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:10.10
88/0264-9381/17/5/309[arXiv:hep-th/9911002 [hep-th]]. ETC.\n\n 12. H. L
. Verlinde and E. P. Verlinde\, Nucl. Phys. B 371\, 246-268 (1992) doi:10.
1016/0550-3213(92)90236-5 [arXiv:hep-th/9110017 [hep-th]].\n\n 13. S. C
arlip\, Phys. Rev. Lett. 82\, 2828-2831 (1999) doi:10.1103/PhysRevLett.82.
2828[arXiv:hep-th/9812013 [hep-th]]. ETC.\n\n 14. S. N. Solodukhin\, Ph
ys. Lett. B 454\, 213-222 (1999) doi:10.1016/S0370-2693(99)00398-6[arXiv:h
ep-th/9812056 [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://stable.researchseminars.org/talk/nhetc/86/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Veronica Pasquarella (University of Cambridge)
DTSTART:20230912T183000Z
DTEND:20230912T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/87
DESCRIPTION:Title: Categorical Symmetries and Fiber Functors from Multiple Condensing H
omomorphisms from 6D N=(2\,0) SCFTs\nby Veronica Pasquarella (Universi
ty of Cambridge) as part of NHETC Seminar\n\n\nAbstract\nhis talk is struc
tured into two parts\, each one exploiting the symmetry topological field
theory/topological order correspondence (SymTFT/TO). On the one hand\, th
is enables to further the understanding of the categorical structure arisi
ng from dimensional reduction of 6D N = (2\, 0) SCFTs\, identifying a crit
erion to distinguish between intrinsic and non-intrinsic non-invertible sy
mmetries in terms of the quantum dimension of condensable algebras. On the
other\, it addresses the issue of determining the fiber functor and Drinf
eld center for a system of joined absolute theories separated by non inver
tible defects. Concluding remarks include the usefulness of these insights
for furthering the understanding of the interplay between gauge theory\,
representation theory and 3D mirror symmetry.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/87/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hao Lan-Xu (Stony Brook University)
DTSTART:20230921T183000Z
DTEND:20230921T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/88
DESCRIPTION:Title: Analyticity 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 theorie
s (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. T
hen the different spectrum scenarios for high-T and low-T domains will be
introduced. Generally speaking\, an IFT which sits not at the critical tem
perature and has a non-vanishing external field is neither solvable nor in
tegrable. However\, it's possible to look into the analytical properties o
f various quantities in the theory space\, then further non-perturbative i
nformation can be extracted. I will focus on the analyticity properties fo
r mass of the first excitation\, and discuss its critical behaviours and d
ispersion relation in both ordered and disordered phase. Finally\, if time
allowed\, I will switch the topic and discuss the analyticity properties
of the analytical structure of S-matrices\, and show various related inter
esting phenomenons together with unsolved questions.\n\nReferences:\n[1] I
sing field theory in a magnetic field: Analytic properties of the free ene
rgy\, P. Fonseca and A. Zamolodchikov\, hep-th/0112167 [hep-th].\n[2] Isin
g Spectroscopy 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-L
ee singularity\, 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. Yi
n\, 1905.00710 [hep-th]\n[5] Ising Field Theory in a Magnetic Field: Exten
ded analyticity properties of M1\, H. Xu\, in preparation.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/88/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michael Winer (University of Maryland)
DTSTART:20230926T183000Z
DTEND:20230926T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/89
DESCRIPTION:Title: The Spectral Form Factor: From Hydrodynamics to the Riemann Zeta Fun
ction\nby Michael Winer (University of Maryland) as part of NHETC Semi
nar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/89/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kathryn Zurek (Caltech)
DTSTART:20231010T183000Z
DTEND:20231010T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/90
DESCRIPTION:by Kathryn Zurek (Caltech) as part of NHETC Seminar\n\nAbstrac
t: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/90/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dan Freed (Harvard)
DTSTART:20231017T183000Z
DTEND:20231017T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/91
DESCRIPTION:Title: What is an anomaly?\nby Dan Freed (Harvard) as part of NHETC Sem
inar\n\n\nAbstract\nAnomalies in quantum field theory have been the subjec
t of attention for decades. In this talk I will dispel some myths: anomal
ies are tied to symmetry\, anomalies are tied to fermionic fields\, etc.
Then I will explain how anomalies--expressed as invertible field theories-
-are the manifestation of the projectivity of quantum field theory. My po
int of view is summarized by a slogan:\n\n Quantum theory is pr
ojective. Quantization is linear.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/91/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eliezer Rabinovici (CERN)
DTSTART:20231024T183000Z
DTEND:20231024T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/92
DESCRIPTION:Title: Some Aspects of Krylov Complexity\nby Eliezer Rabinovici (CERN)
as part of NHETC Seminar\n\n\nAbstract\nA review of the concept of Krylov
Complexity (K-Complexity) will be presented. One feature of K-Complexity i
s that its definition does not involve a tolerance parameter. I will descr
ibe some general properties of K-Complexity\, its behavior when interpolat
ing among various types of systems: free\, strongly integrable and chaotic
ones. Finally for a certain low dimensional system in a certain state I w
ill describe an explicit derivation of the geometric bulk dual of K comple
xity.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/92/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brian Swingle (Brandeis)
DTSTART:20231114T193000Z
DTEND:20231114T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/93
DESCRIPTION:by Brian Swingle (Brandeis) as part of NHETC Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/93/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Akshay Ghalsasi (University of Pittsburgh)
DTSTART:20230919T183000Z
DTEND:20230919T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/94
DESCRIPTION:Title: Gravitational Waves from NNaturalness\nby Akshay Ghalsasi (Unive
rsity of Pittsburgh) as part of NHETC Seminar\n\n\nAbstract\nNNaturalness
provides a solution to the hierarchy problem by having large number of cop
ies of the standard model. The reheating mechanism is NNaturalness provide
s energy density to each of these sectors. The sectors in NNaturalness whi
ch have a positive Higgs mass squared have massless quarks and hence can u
ndergo a first order phase transition. The resultant gravitational waves c
an be observable by future gravitational wave observatories providing a un
ique window into NNaturalness. I this talk\, I will describe the NNaturaln
ess mechanism\, and the parameter space of NNaturalness that can be probed
by future GW observatories.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/94/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yitian Sun (MIT)
DTSTART:20231026T183000Z
DTEND:20231026T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/95
DESCRIPTION:by Yitian Sun (MIT) as part of NHETC Seminar\n\nAbstract: TBA\
n
LOCATION:https://stable.researchseminars.org/talk/nhetc/95/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shu-Heng Shao (Stony Brook University)
DTSTART:20231031T183000Z
DTEND:20231031T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/96
DESCRIPTION:Title: Non-invertible lattice translation\nby Shu-Heng Shao (Stony Broo
k University) as part of NHETC Seminar\n\n\nAbstract\nI will discuss non-i
nvertible symmetries in 1+1d lattice models with a tensor-product Hilbert
space\, including the transverse-field Ising model and its deformation. Th
e Kramers-Wannier duality operator on the lattice mixes with the lattice t
ranslation\, and obeys a different non-invertible algebra compared to the
continuum one.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/96/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ahsan Khan (IAS)
DTSTART:20231214T193000Z
DTEND:20231214T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/97
DESCRIPTION:Title: Holomorphic Surface Defects in 4d Chern-Simons Theory and the Bethe
Equations\nby Ahsan Khan (IAS) as part of NHETC Seminar\n\n\nAbstract\
nThere is a remarkable relationship between integrable systems in 1+1 dime
nsions (such as the Heisenberg spin chain) and a certain quantum gauge the
ory in four dimensions often referred to as four-dimensional Chern-Simons
Theory. I will review aspects of this relationship and then describe some
newer results involving holomorphic surface defects in this gauge theory a
nd their relationship to the Bethe equations governing spin chains.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/97/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Brennan (UC San Diego)
DTSTART:20231128T193000Z
DTEND:20231128T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/98
DESCRIPTION:Title: The Callan Rubakov Effect\nby Daniel Brennan (UC San Diego) as p
art of NHETC Seminar\n\n\nAbstract\nThe Callan Rubakov Effect describes th
e interaction between (massless) fermions and a smooth monopole in 4d gaug
e theory. In this scenario\, the fermions can probe the UV physics inside
the monopole core which leads to interesting effects such as proton decay
in GUT models. However\, the monopole-fermion scattering appears to lead t
o out-states that are not in the perturbative Hilbert space. In this talk\
, we will review this issue and propose a new physical mechanism that reso
lves this long-standing confusion.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/98/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francois Lanusse (CNRS)
DTSTART:20231205T193000Z
DTEND:20231205T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/99
DESCRIPTION:by Francois Lanusse (CNRS) as part of NHETC Seminar\n\nAbstrac
t: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/99/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kevin Costello (Perimeter Institute)
DTSTART:20231107T193000Z
DTEND:20231107T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/100
DESCRIPTION:Title: Burns space and celestial holography\nby Kevin Costello (Perime
ter Institute) as part of NHETC Seminar\n\n\nAbstract\nCelestial holograph
y aims to describe scattering amplitudes of theories on asymptotically fla
t space times in terms of two-dimensional CFTs. I will describe an explici
t top-down example\, where correlators of a 2d chiral CFT at large N match
amplitudes of a 4d theory on an asymptotically flat manifold known as Bur
ns space.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/100/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lotte Hollands (Heriot-Watt University)
DTSTART:20231219T193000Z
DTEND:20231219T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/101
DESCRIPTION:Title: Non-perturbative partition functions for N=2 theories of class S\nby Lotte Hollands (Heriot-Watt University) as part of NHETC Seminar\n\n
\nAbstract\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 theories in terms of certain configurations of curves on a Riemann sur
face\, called spectral networks. In this talk I'll review how to generate
a spectral network for each point of the 4d Coulomb branch together with t
he choice of a phase. I'll point out that this data corresponds to a bound
ary condition for the 4d N=2 theory in the half-Omega background\, and ass
ociate to it a new kind of N=2 partition function. This partition function
is locally constant in the phase\, while its jumps are associated to 4d B
PS particles in the corresponding Coulomb vacuum. The well-known Nekrasov
partition function (in the half-Omega background) may be recovered in a we
akly coupled region of the Coulomb branch (if the theory admits any)\, at
a special phase corresponding to a Fenchel-Nielsen spectral network. When
lifted to five dimensions\, this new partition function becomes the non-pe
rturbative topological string partition function.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/101/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zohar Komargodski (SCGP)
DTSTART:20240123T193000Z
DTEND:20240123T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/102
DESCRIPTION:Title: The dynamics on Defects in Magnets and Gauge Theories\nby Zohar
Komargodski (SCGP) as part of NHETC Seminar\n\n\nAbstract\nWe define a no
tion of zero-temperature entropy for impurities (line defects) in d + 1 sp
ace-time dimensions. We show that this entropy obeys a simple evolution eq
uation under the renormalization group. We apply this result for impuritie
s in magnets and in gauge theories. We find new critical impurities and ph
ase transitions. We also discuss constraints from topology on the dynamics
of defects and apply topology for the problem of spontaneous symmetry bre
aking and the Kondo problem in a 2+1 dimensional quantum magnet.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/102/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carolina Figueiredo (Princeton)
DTSTART:20240130T193000Z
DTEND:20240130T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/103
DESCRIPTION:Title: Scalars to Pions and Gluons: New structure closer to the real world
\nby Carolina Figueiredo (Princeton) as part of NHETC Seminar\n\n\nAbs
tract\nScattering amplitudes for the simplest theory of colored scalars—
Tr phi^3 theory — have been understood as arising from a counting probl
em associated with curves on a surface (arXiv:2309.15913v1). This formulat
ion produces “stringy” integrals for the amplitudes\, built off of var
iables defined on the surface\, from which the field theory limit as $\\al
pha^\\prime \\to 0$ can easily be extracted. In this talk\, we will extend
this approach to theories closer to the real world — in particular the
non-linear sigma model and Yang-Mills theory (arXiv:2401.00041v1). We will
explain how amplitudes in these theories are surprisingly obtained from t
hose of the Tr $\\phi^3$ theory by simple shifts of the kinematic data. W
e will also explain how these “stringy” formulations expose universal
features of the amplitudes present in all these colored theories — rangi
ng from hidden patterns of zeroes to unusual factorization properties away
from singularities (arXiv:2312.16282v1).\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/103/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ofer Aharony (Weizmann and IAS)
DTSTART:20240213T193000Z
DTEND:20240213T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/104
DESCRIPTION:Title: Two dimensional QCD as a string theory\nby Ofer Aharony (Weizma
nn and IAS) as part of NHETC Seminar\n\n\nAbstract\n50 years after the dua
lity 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 gaug
e theory. I will review work in progress on two approaches to understandin
g this\, in what should perhaps be the simplest case\, namely two dimensio
nal gauge theories. The first approach uses perturbation theory to obtain
an effective stringy description of the high-energy states of 2d QCD with
very massive adjoint fermions. The second approach starts from finding a g
ood worldsheet description for the string dual to the two dimensional pure
Yang-Mills theory\, following past work by Gross-Taylor\, Cordes-Moore-Ra
mgoolam\, and Horava\; in the future we hope to add to it boundaries (quar
ks in the fundamental representation) and/or extra particles on the worlds
heet (adjoint matter fields).\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/104/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francois Lanusse (CNRS)
DTSTART:20240326T183000Z
DTEND:20240326T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/105
DESCRIPTION:by Francois Lanusse (CNRS) as part of NHETC Seminar\n\nAbstrac
t: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/105/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Iñaki Garcia-Etxebarria (Durham\, UK)
DTSTART:20240402T183000Z
DTEND:20240402T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/106
DESCRIPTION:Title: Deriving SymTFTs from geometry\nby Iñaki Garcia-Etxebarria (Du
rham\, UK) as part of NHETC Seminar\n\n\nAbstract\nSymTFTs (or\, relatedly
\, the "sandwich construction") have emerged recently as a useful way to t
hink of categorical symmetries. I will give a brief description of this co
nstruction\, and then review recent work on how to obtain the SymTFT data
from geometry in the context of geometric engineering.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/106/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ibrahima Bah (Johns Hopkins)
DTSTART:20240423T183000Z
DTEND:20240423T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/107
DESCRIPTION:Title: Aspects of topological symmetry\, holography\, and branes\nby I
brahima Bah (Johns Hopkins) as part of NHETC Seminar\n\n\nAbstract\nIn thi
s talk I will discuss the holographic duals of topological operators. At
low energy sugra\, they can be realized by Page charge associated to Gauss
law constraints. In the UV string theory\, topological operators can be
characterized by various brane configurations. This provides a way of exp
loring generalized symmetries with dynamical bulk physics.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/107/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Iñaki Garcia-Etxebarria (Durham)
DTSTART:20240507T183000Z
DTEND:20240507T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/108
DESCRIPTION:Title: Deriving SymTFTs from geometry\nby Iñaki Garcia-Etxebarria (Du
rham) as part of NHETC Seminar\n\n\nAbstract\nSymTFTs (or\, relatedly\, th
e "sandwich construction") have emerged recently as a useful way to think
of categorical symmetries. I will give a brief description of this constru
ction\, and then review recent work on how to obtain the SymTFT data from
geometry in the context of geometric engineering.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/108/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hao Zhang (University of Tokyo)
DTSTART:20240910T183000Z
DTEND:20240910T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/109
DESCRIPTION:by Hao Zhang (University of Tokyo) as part of NHETC Seminar\n\
nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/109/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Jafferis (Harvard)
DTSTART:20240924T183000Z
DTEND:20240924T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/110
DESCRIPTION:by Daniel Jafferis (Harvard) as part of NHETC Seminar\n\nAbstr
act: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/110/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nathan Seiberg (IAS)
DTSTART:20241001T183000Z
DTEND:20241001T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/111
DESCRIPTION:by Nathan Seiberg (IAS) as part of NHETC Seminar\n\nAbstract:
TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/111/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eliezer Rabinovici (The Racah Institute of Physics)
DTSTART:20241015T183000Z
DTEND:20241015T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/112
DESCRIPTION:by Eliezer Rabinovici (The Racah Institute of Physics) as part
of NHETC Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/112/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ping Gao (Rutgers)
DTSTART:20250909T183000Z
DTEND:20250909T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/113
DESCRIPTION:Title: A new probe of non-maximal quantum chaos: pole-skipping of higher s
pin operators\nby Ping Gao (Rutgers) as part of NHETC Seminar\n\n\nAbs
tract\nPole-skipping is an independent probe of quantum chaos beyond the L
yapunov exponent. In this talk\, I will explain the pole-skipping of highe
r spin operators in a higher-dimensional CFT with large N. For such a CFT
in the Regge limit\, we will have non-maximal quantum chaos\, which is ass
ociated with the leading Regge trajectory. For generic spin J\, there exis
ts a nontrivial two-piece rule for the distribution of pole-skipping point
s at both positive and negative imaginary frequencies. For the pole-skippi
ng of an individual spin J operator\, it has nothing to do with the non-ma
ximal Lyapunov exponent. However\, if we combine the infinite pole-skippin
g points with the largest imaginary Matsubara frequencies\, we will surpri
singly find that they form an analytic trajectory\, which gives the non-ma
ximal Lyapunov exponent. We conjecture this property holds for generic non
-maximal chaotic systems and verify this conjecture in large q SYK chain.\
n
LOCATION:https://stable.researchseminars.org/talk/nhetc/113/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brandon Rayhaun (IAS)
DTSTART:20250923T183000Z
DTEND:20250923T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/114
DESCRIPTION:Title: Anomalies of Defect Parameter Spaces and a Spin-Flux Duality\nb
y Brandon Rayhaun (IAS) as part of NHETC Seminar\n\n\nAbstract\nI will int
roduce the notion of an anomaly in the space of defect coupling constants\
, generalizing an analogous construction of Cordova\, Freed\, Lam\, and Se
iberg. I will explain how such anomalies\, together with more standard 't
Hooft anomalies and the irreversibility of the renormalization group\, can
be used to constrain the IR phases of defects in familiar quantum field t
heories. As an example\, I will use these techniques to provide evidence f
or a conjectural "spin-flux duality" which describes how certain line oper
ators are mapped across particle/vortex duality in 2+1d.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/114/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anatoly Dymarsky (Kentucky)
DTSTART:20251007T183000Z
DTEND:20251007T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/115
DESCRIPTION:Title: Abelian TQFTs\, codes\, and holography\nby Anatoly Dymarsky (Ke
ntucky) as part of NHETC Seminar\n\n\nAbstract\nIn the first part\, I will
show how anyon condensation in 3D and 5D Abelian TQFTs naturally gives ri
se to both classical and quantum (error-correcting) codes\, and I will the
n explain how codes emerge to describe the TQFT path integral on manifolds
with boundary. In the second part\, I will explain how 3D TQFTs can be co
nsistently summed over all topologies\, leading to a well-defined holograp
hic dual. If time permits\, I will conclude with a discussion of a mass fo
rmula that evaluates the number of topological boundary conditions from th
e partition function of TQFT gravity.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/115/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hongwan Liu (Boston)
DTSTART:20250930T183000Z
DTEND:20250930T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/116
DESCRIPTION:Title: Doing BBN Better\nby Hongwan Liu (Boston) as part of NHETC Semi
nar\n\n\nAbstract\nBig Bang Nucleosynthesis (BBN) is a cornerstone of mode
rn cosmology\, providing us with invaluable information about our cosmolog
ical history. In this talk\, I will discuss some recent and ongoing work a
imed at bringing BBN fully into the era of precision cosmology.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/116/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vladimir Rosenhaus (CUNY)
DTSTART:20251021T183000Z
DTEND:20251021T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/117
DESCRIPTION:Title: Renormalization Group in far-from-equilibrium states\nby Vladim
ir Rosenhaus (CUNY) as part of NHETC Seminar\n\n\nAbstract\nWe study renor
malization group flows in far-from-equilibrium states. The study is made t
ractable by focusing on states that are spatially homogeneous\, time-indep
endent\, and scale invariant. Such states\, in which mode k has occupation
number $n_k = k^{-\\gamma}$\, are well-known in nonlinear physics (going
under the name of wave turbulence). RG flow in such states is qualitativel
y different than in the vacuum -- a positive $\\gamma$ decreases the dimen
sion of an operator\, turning marginal interactions into relevant interact
ions. We compute one loop beta functions. Depending on the sign of the bet
a function\, backreaction may either cause a minor shift of the state in t
he IR\, or completely change the nature of the state. Focusing on nearly m
arginal interactions\, we construct an analog of the epsilon expansion and
IR fixed points\, with epsilon now set by the scaling of the interaction
rather than the spacetime dimension. In the language of RG flow\, critical
balance scaling -- having applications in fields as varied as astrophysic
s and ocean waves -- corresponds to the state dynamically adjusting itself
along the RG flow until the interaction becomes marginal.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/117/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Meng Cheng (Yale)
DTSTART:20251028T183000Z
DTEND:20251028T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/118
DESCRIPTION:Title: Ordering topological orders in quantum Hall systems and beyond\
nby Meng Cheng (Yale) as part of NHETC Seminar\n\n\nAbstract\nI will discu
ss possible topological order/topological quantum field theory of quantum
Hall systems. Given the value of the Hall conductivity\, we constrain the
global symmetry of the low-energy theory and its anomaly. This information
is powerful enough to lead to a unique minimal topological order (or a sm
all number of minimal topological orders)\, and generally provides an orga
nizing principle for possible topological phases in these systems. Almost
all of the known experimentally discovered topological orders are these mi
nimal theories. I will also discuss applications of these ideas in lattice
systems of fermions with a given filling factor.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/118/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sahand Seifnashri (IAS)
DTSTART:20251104T193000Z
DTEND:20251104T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/119
DESCRIPTION:Title: Symmetry Transmutation\nby Sahand Seifnashri (IAS) as part of N
HETC Seminar\n\n\nAbstract\nWe begin with a review of generalized global s
ymmetries and some of their applications. Next\, we describe the phenomeno
n of symmetry transmutation\, in which an ordinary global symmetry in the
UV theory transmutes into a generalized higher-form symmetry in the effect
ive low-energy theory. Notably\, transmuted symmetries are exact rather th
an accidental. We then discuss gauge theory examples in which the anomaly
of the UV symmetry is matched by the anomaly of the transmuted symmetry in
the IR. Finally\, we discuss symmetry transmutation in QCD.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/119/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anirudh Prabhu (Princeton)
DTSTART:20251118T193000Z
DTEND:20251118T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/120
DESCRIPTION:by Anirudh Prabhu (Princeton) as part of NHETC Seminar\n\nAbst
ract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/120/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Keisuke Inomata (Johns Hopkins)
DTSTART:20251125T193000Z
DTEND:20251125T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/121
DESCRIPTION:Title: Self-scattering of inflaton during inflation\nby Keisuke Inomat
a (Johns Hopkins) as part of NHETC Seminar\n\n\nAbstract\nInflationary mod
els predicting a scale-dependent large amplification of the density pertur
bations have recently attracted a lot of attention because the amplified p
erturbations can seed a sizable amount of primordial black holes and stoch
astic background of gravitational waves. While power spectra in these mode
ls are often computed ignoring the inflaton self-scattering\, the self-sca
ttering (or loop correction) is generally non-negligible in such inflation
models with large amplification of perturbations. In this talk\, I will h
ighlight what changes and remains unchanged by inflaton self-scattering du
ring inflation.\nReferences: arXiv:2211.02586\, 2403.04682\, 2403.12811\,
2502.08707\, and 2502.12112\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/121/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nima Laal (Vanderbilt)
DTSTART:20251209T193000Z
DTEND:20251209T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/122
DESCRIPTION:by Nima Laal (Vanderbilt) as part of NHETC Seminar\n\nAbstract
: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/122/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aurelien Dersy (Harvard)
DTSTART:20251014T183000Z
DTEND:20251014T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/123
DESCRIPTION:Title: Learning the Language of Scattering Amplitudes\nby Aurelien Der
sy (Harvard) as part of NHETC Seminar\n\n\nAbstract\nMachine learning (ML)
has grown dramatically in high-energy physics in recent years. Tasks such
as classification\, regression\, anomaly detection\, and density estimati
on now benefit from modern ML approaches that often outperform traditional
baselines. Far less attention\, however\, has gone to the theoretical sid
e\, even though (symbolic) data is plentiful. In this talk\, I will discus
s how modern models can help bridge this gap and “learn the language”
of scattering amplitudes. In particular\, I will describe recent work on s
implifying amplitude expressions\, reconstructing S-matrix phases\, and re
covering exact analytic formulas.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/123/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Adrian Bayer (Princeton)
DTSTART:20251111T193000Z
DTEND:20251111T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/124
DESCRIPTION:by Adrian Bayer (Princeton) as part of NHETC Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/124/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jeff Harvey (Chicago)
DTSTART:20251202T193000Z
DTEND:20251202T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/125
DESCRIPTION:Title: Level-Rank Duality\, Anyon Condensation\, and Holomorphic CFT\n
by Jeff Harvey (Chicago) as part of NHETC Seminar\n\n\nAbstract\nI will di
scuss relations between the three topics in the title.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/125/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nathan Seiberg (IAS)
DTSTART:20260120T193000Z
DTEND:20260120T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/126
DESCRIPTION:Title: Symmetry\, Anomaly\, Gauging\, Proliferation\, and Condensation
\nby Nathan Seiberg (IAS) as part of NHETC Seminar\n\n\nAbstract\nIn the s
tudy of topological quantum field theories in 2+1 dimensions\, it is commo
n to\nperform an operation known as “anyon condensation.” This term is
misleading. Two\nmore appropriate terms for this operation are “gauging
a one-form symmetry” or “anyon\nproliferation.” Interestingly\, the
se two terms are similar\, but not identical. We will clarify\nthese diffe
rent notions and use this insight to analyze various phase transitions out
of a\ngiven topological order.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/126/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carolina Figueiredo (Princeton)
DTSTART:20260127T193000Z
DTEND:20260127T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/127
DESCRIPTION:Title: Large $n$: scattering amplitudes at large multiplicity\nby Caro
lina Figueiredo (Princeton) as part of NHETC Seminar\n\n\nAbstract\nWhat h
appens when we scatter a large number $n$ of particles\, say with $n = 10^
1000$? This question is out of reach of all existing approaches to scatter
ing amplitudes\, whether directly through Feynman diagrams or recursion re
lations. In this talk\, I will study this problem at tree-level for a simp
le scalar theory\, Tr($\\phi^3$) theory\, and describe a new way of access
ing this regime\, starting from the "tropical" representation of the ampli
tudes given by the formalism of surfaceology. Remarkably\, we find that a
t large $n$ the sum over diagrams "smooths out". Working at leading order
in $n$\, and in certain "positive" regions of kinematic space\, the final
answer is astonishingly simple\, given by a single term\, determined by an
optimization problem associated with a biased random walk. I will also de
scribe a transformation from the tropical representation to a new "dual" t
heory for amplitudes\, which in simple limits reduces to the motion of a p
article on a half-line\, evolving for a "time'' $n$\, allowing us to syste
matically extract the $1/n$ expansion of the amplitude. I will end by expl
aining how these results generalize to other large $n$ contexts\, from the
scattering of pions\, to string scattering at ultra-high energies.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/127/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Subhajit Ghosh (UT Austin)
DTSTART:20260203T193000Z
DTEND:20260203T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/128
DESCRIPTION:by Subhajit Ghosh (UT Austin) as part of NHETC Seminar\n\nAbst
ract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/128/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Patrick Draper (UIUC)
DTSTART:20260210T193000Z
DTEND:20260210T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/129
DESCRIPTION:by Patrick Draper (UIUC) as part of NHETC Seminar\n\nAbstract:
TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/129/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hong Liu (MIT)
DTSTART:20260303T193000Z
DTEND:20260303T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/130
DESCRIPTION:Title: "Filtering" CFTs at large N: Euclidean Wormholes\, Closed Universes
\, and Black Hole Interiors\nby Hong Liu (MIT) as part of NHETC Semina
r\n\n\nAbstract\nDespite its successes\, the large-N holographic dictionar
y remains incomplete. Key features of gravitational path integrals--most n
otably Euclidean wormholes and the associated failure of factorization--la
ck a clear interpretation in the standard large-N framework. In this talk\
, we discuss a resolution of the puzzle by introducing a large-N filter\,
which provides an intrinsic boundary definition of gravitational "averages
\,'' and a boundary explanation of the origin of wormholes as well as thei
r amplitudes. In addition\, we derive an infinite tower of inequalities co
nstraining wormhole amplitudes. \n\nBeyond resolving factorization\, the l
arge-N filter supplies a generalized framework from which richer Lorentzia
n spacetime structures can emerge\, including closed universes and black h
ole interiors. We argue that both closed universes and black hole interior
s are quantum volatile\, and that an AdS spacetime entangled with a baby u
niverse is likewise quantum volatile. This volatility may allow an observe
r in AdS to infer the existence of the baby universe\, whereas for an infa
lling observer crossing a black hole horizon\, the ability to make measure
ments after may become fundamentally limited--even if they may not live l
ong enough to notice.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/130/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Iñaki García Etxebarria (Durham University)
DTSTART:20260310T183000Z
DTEND:20260310T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/131
DESCRIPTION:Title: Symmetry TFTs for Continuous Spacetime Symmetries\nby Iñaki Ga
rcía Etxebarria (Durham University) as part of NHETC Seminar\n\n\nAbstrac
t\nI will discuss our recent proposal for the Symmetry Topological Field T
heory (SymTFT) for global\, continuous spacetime symmetries (https://arxiv
.org/abs/2509.07965). For a d-dimensional theory\, it is given by a (d + 1
)-dimensional BF-theory for the spacetime symmetry group\, and whenever d
is even\, it includes also Chern-Simons couplings\, that encode conformal
and gravitational anomalies. This proposal is supported by the similarity
to two-dimensional Jackiw-Teitelboim gravity in the d = 1 case and the top
ological limit of four-dimensional gravity in the d = 3 case. I will discu
ss how topological defects constructed from this SymTFT act by applying th
e associated spacetime symmetry transformation. Finally\, I will discuss t
he relation to gravity and holography.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/131/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shu-Heng Shao (MIT)
DTSTART:20260324T183000Z
DTEND:20260324T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/132
DESCRIPTION:Title: Lattice chiral symmetry from bosons in 3+1d\nby Shu-Heng Shao (
MIT) as part of NHETC Seminar\n\n\nAbstract\nWe present an explicit Hami
ltonian that realizes an exact lattice chiral $U(1)_V \\times U(1)_A$ rece
ntly proposed. Nielsen-Ninomiya-type no-go theorems are evaded by using la
ttice bosons rather than fermions. The continuum limit is a compact boson
field theory with an axion-like coupling. While $U(1)_V$ shifts the lattic
e scalar\, $U(1)_A$ acts on short axion string excitations. We demonstrate
the chiral anomaly by showing that $U(1)_A$ is broken when $U(1)_V$ is ga
uged. Finally\, gauging either $U(1)_V$ and $U(1)_A$ leads to lattice non-
invertible and 2-group symmetries\, respectively.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/132/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marius Kongsore (New York University)
DTSTART:20260407T183000Z
DTEND:20260407T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/133
DESCRIPTION:by Marius Kongsore (New York University) as part of NHETC Semi
nar\n\nInteractive livestream: https://rutgers.zoom.us/j/94699297301?pwd=S
VJieHRUYUtmZmRCbGZKQlBTMTRPdz09\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/133/
URL:https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRP
dz09
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ibrahima Bah (Johns Hopkins University)
DTSTART:20260414T183000Z
DTEND:20260414T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/134
DESCRIPTION:by Ibrahima Bah (Johns Hopkins University) as part of NHETC Se
minar\n\nInteractive livestream: https://rutgers.zoom.us/j/94699297301?pwd
=SVJieHRUYUtmZmRCbGZKQlBTMTRPdz09\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/134/
URL:https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRP
dz09
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthias Gaberdiel (ETH Zurich)
DTSTART:20260421T183000Z
DTEND:20260421T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/135
DESCRIPTION:by Matthias Gaberdiel (ETH Zurich) as part of NHETC Seminar\n\
nInteractive livestream: https://rutgers.zoom.us/j/94699297301?pwd=SVJieHR
UYUtmZmRCbGZKQlBTMTRPdz09\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/135/
URL:https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRP
dz09
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sarunas Verner (U. Chicago)
DTSTART:20260428T183000Z
DTEND:20260428T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/136
DESCRIPTION:by Sarunas Verner (U. Chicago) as part of NHETC Seminar\n\nInt
eractive livestream: https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUt
mZmRCbGZKQlBTMTRPdz09\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/136/
URL:https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRP
dz09
END:VEVENT
BEGIN:VEVENT
SUMMARY:Walter Tangrife (Loyola University\, Chicago)
DTSTART:20260505T183000Z
DTEND:20260505T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/137
DESCRIPTION:by Walter Tangrife (Loyola University\, Chicago) as part of NH
ETC Seminar\n\nInteractive livestream: https://rutgers.zoom.us/j/946992973
01?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRPdz09\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/137/
URL:https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRP
dz09
END:VEVENT
BEGIN:VEVENT
SUMMARY:Melissa Diamond (McGill)
DTSTART:20260512T183000Z
DTEND:20260512T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/138
DESCRIPTION:by Melissa Diamond (McGill) as part of NHETC Seminar\n\nIntera
ctive livestream: https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZm
RCbGZKQlBTMTRPdz09\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/138/
URL:https://rutgers.zoom.us/j/94699297301?pwd=SVJieHRUYUtmZmRCbGZKQlBTMTRP
dz09
END:VEVENT
BEGIN:VEVENT
SUMMARY:Moritz Münchmeyer (University of Wisconsin-Madison)
DTSTART:20260217T193000Z
DTEND:20260217T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/140
DESCRIPTION:Title: AI Reasoning in Theoretical Physics with TPBench and MadEvolve\
nby Moritz Münchmeyer (University of Wisconsin-Madison) as part of NHETC
Seminar\n\n\nAbstract\nLarge-language models are now powerful enough to as
sist physicists with mathematical reasoning at research level. In this tal
k\, I will first present our dataset TPBench (tpbench.org)\, which was con
structed to benchmark and improve AI models specifically for theoretical p
hysics. I will then discuss how test-time scaling and symbolic verificatio
n can be used to improve their performance and reliability. In the second
part of my talk I will present MadEvolve\, our new LLM-based system to ite
ratively improve scientific algorithms. I will show that MadEvolve can set
state-of-the-art results for algorithms in computational cosmology\, such
as the reconstruction of initial conditions of the universe. Finally\, I
will briefly present preliminary work on reinforcement learning fine-tunin
g of reasoning for theoretical physics.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/140/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuan-Sen Ting (Ohio State University)
DTSTART:20260224T193000Z
DTEND:20260224T203000Z
DTSTAMP:20260404T111008Z
UID:nhetc/141
DESCRIPTION:by Yuan-Sen Ting (Ohio State University) as part of NHETC Semi
nar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/141/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Harlow (MIT)
DTSTART:20260317T183000Z
DTEND:20260317T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/142
DESCRIPTION:Title: Observers\, alpha parameters\, and the Hartle-Hawking state\nby
Daniel Harlow (MIT) as part of NHETC Seminar\n\n\nAbstract\nIn this talk
I will clear up some misunderstandings about the gravitational path integr
al and quantum gravity in a closed universe. I will explain that there ar
e really three inequivalent versions of the path integral\, each of which
appears in various applications. For example I will explain why the close
d string Hilbert space is not one-dimensional\, and also why Coleman's \\a
lpha-parameters do not resolve the black hole information problem. I will
explain a connection between recent proposals for using an observer to re
solve the one-dimensional Hilbert space problem and the coarse-grained spe
ctral form factor in AdS/CFT\, and I will also explain the (nontrivial) re
lationship between the Hartle-Hawking state and the unique state of hologr
aphic cosmology.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/142/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mariel Pettee (Ohio State University)
DTSTART:20260331T183000Z
DTEND:20260331T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/143
DESCRIPTION:by Mariel Pettee (Ohio State University) as part of NHETC Semi
nar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/143/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuan-Sen Ting (Ohio State University)
DTSTART:20260312T183000Z
DTEND:20260312T193000Z
DTSTAMP:20260404T111008Z
UID:nhetc/144
DESCRIPTION:Title: Expediting Astronomical Discovery with AI Agents\nby Yuan-Sen T
ing (Ohio State University) as part of NHETC Seminar\n\n\nAbstract\nThe ex
pansive\, interdisciplinary nature of astronomy\, combined with its open-a
ccess culture\, makes it an ideal testing ground for exploring how Large L
anguage Models (LLMs) can accelerate scientific discovery. In this talk\,
I will present our recent advances in applying LLMs as autonomous research
agents. We demonstrate that AI agents now achieve gold-medal performance
on International Astronomy Olympiad problems\, and that multi-agent framew
orks like Mephisto can conduct end-to-end galaxy spectral fitting—iterat
ively refining physical models and accumulating knowledge through self-pla
y\, approaching human-like intuition and domain reasoning. However\, the M
oravec paradox manifests clearly: tasks requiring abstract calculation may
be easier for AI than seemingly simple perceptual tasks like chart readin
g and visual reasoning\, which remain key bottlenecks. To address the cost
barrier at scale\, we developed open-source specialized models (AstroSage
) that match frontier performance on astronomy Q&A at a fraction of the co
st. I will conclude by reflecting on the epistemological implications—wh
at counts as knowledge and understanding when AI agents can reason but not
yet perceive the way scientists do\, and what this means for the future o
f astronomical discovery.\n
LOCATION:https://stable.researchseminars.org/talk/nhetc/144/
END:VEVENT
END:VCALENDAR