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BEGIN:VEVENT
SUMMARY:Dongmin Gang (APCTP)
DTSTART;VALUE=DATE-TIME:20200420T080000Z
DTEND;VALUE=DATE-TIME:20200420T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/1
DESCRIPTION:Title: Twisted indices in 3d-3d correspondence\nby Dongmin Gang
(APCTP) as part of KIAS String Seminars\n\n\nAbstract\nI will talk about 3
d-3d relation for twisted indices on general Riemann surface and its appli
cations to i) microstates counting of supersymmetric blackholes and ii) ma
thematics of Reidermeister torsion on hyperbolic 3-manifolds.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yu Nakayama (Rikkyo University)
DTSTART;VALUE=DATE-TIME:20200506T080000Z
DTEND;VALUE=DATE-TIME:20200506T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/2
DESCRIPTION:Title: Supersymmetric CP-violating Weyl anomaly\nby Yu Nakayama
(Rikkyo University) as part of KIAS String Seminars\n\n\nAbstract\nIn CP-v
iolating conformal field theories in four dimensions\, the Pontryagin dens
ity can appear in the Weyl anomaly. The Pontryagin density in the Weyl ano
maly is consistent\, but it has a peculiar feature that the parent three-p
oint function of the energy-momentum tensor can violate CP only (semi-)loc
ally.\n\nIn this talk\, I present our recent studies (with K. Nakagawa) on
the supersymmetric completion of the Pontryagin density in the Weyl anoma
ly\, where the central charge c effectively becomes a complex number. I al
so introduce a recent debate over if a Weyl fermion in four-dimensions may
or may not have the Pontryagin density in the Weyl anomaly.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dongsu Bak (KIAS & U. of Seoul)
DTSTART;VALUE=DATE-TIME:20200511T080000Z
DTEND;VALUE=DATE-TIME:20200511T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/3
DESCRIPTION:Title: Traversable wormholes and quantum gravity lab on the tabletop
\nby Dongsu Bak (KIAS & U. of Seoul) as part of KIAS String Seminars\n
\n\nAbstract\nIn this talk I will introduce the traversable wormholes whic
h is related to quantum teleportation. I shall explain how the traversable
wormholes can be realized in the 2d JT gravity theory\, which is dual to
two interacting SYK quantum systems. I will show how to confirm experiment
ally the existence of the bulk wormhole with a simple set of operators in
the quantum mechanics side.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seok Kim (Seoul National University)
DTSTART;VALUE=DATE-TIME:20200608T080000Z
DTEND;VALUE=DATE-TIME:20200608T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/4
DESCRIPTION:Title: Microstates of AdS black holes\nby Seok Kim (Seoul Nation
al University) as part of KIAS String Seminars\n\n\nAbstract\nI will expla
in some solved/unsolved problems on the QFT dual microstates of BPS black
holes in AdS5 x S5. The problem reduces to understanding the local BPS ope
rators of the field theory at weak coupling. From the index\, one sees a f
ast growth of such states which accounts for the black hole entropy. I con
cretely illustrate this fact (and other related ideas) by numerically stud
ying the index up to U(6) gauge groups. I will then explain a yet unsolved
problem\, of explicitly constructing such operators in the cohomological
setup.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vasilis Niarchos (University of Crete)
DTSTART;VALUE=DATE-TIME:20200518T080000Z
DTEND;VALUE=DATE-TIME:20200518T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/5
DESCRIPTION:Title: Matching type-B conformal anomalies\nby Vasilis Niarchos
(University of Crete) as part of KIAS String Seminars\n\n\nAbstract\nI wil
l revisit the standard type-A and type-B classification of\nconformal anom
alies in conformal field theory. There are general arguments\nthat show th
at type-A conformal anomalies are very similar to chiral\nanomalies and th
at they match in different phases of a theory. Such\narguments do not gene
ralize to type-B anomalies\, which are expected to\ndepend on the phase of
the theory. Contrary to this general expectation\, I\nwill present a new
formal argument that can be used to prove the\nnon-perturbative matching o
f a certain class of type-B conformal anomalies\nin 4d N=2 super-conformal
field theories along the Higgs branch. In such\ncases the corresponding a
nomalies are non-trivial functions of exactly\nmarginal coupling constants
that can be computed using methods of\nsupersymmetric localisation.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wei Li (Beijing\, Inst. Theor. Phys.)
DTSTART;VALUE=DATE-TIME:20200615T080000Z
DTEND;VALUE=DATE-TIME:20200615T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/6
DESCRIPTION:Title: Quiver Yangian from crystal melting\nby Wei Li (Beijing\,
Inst. Theor. Phys.) as part of KIAS String Seminars\n\n\nAbstract\nThe BP
S counting of type IIA string theory on non-compact toric Calabi-Yau three
folds can be described by crystal melting. I will explain how to construct
the BPS algebras for these theories by a “bootstrap" method\, where one
solves for the algebra by demanding that it acts on the corresponding BPS
crystal appropriately. The resulting algebras are quiver Yangians Y(Q\,W)
that are associated with the quiver and the superpotential of the theory.
Based on joint work with M. Yamazaki (arxiv: 2003.08909).\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carlos Nunez (Swansea University)
DTSTART;VALUE=DATE-TIME:20200525T080000Z
DTEND;VALUE=DATE-TIME:20200525T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/7
DESCRIPTION:Title: Aspects of gauge-strings duality\nby Carlos Nunez (Swanse
a University) as part of KIAS String Seminars\n\n\nAbstract\nI will discus
s aspects of super conformal field theories in diverse dimensions. The foc
us will be on theories in four\, six and two dimensions. I will use a hol
ographic perspective to present the topics. Some aspects of Integrability
and RG flows away from the CFTs will be discussed. If time allows\, the ca
se of super conformal quantum mechanics will be addressed. This talk is ba
sed on papers I published in the last year.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiara Toldo (Ecole Polytechnique)
DTSTART;VALUE=DATE-TIME:20200629T080000Z
DTEND;VALUE=DATE-TIME:20200629T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/8
DESCRIPTION:Title: Spinning BPS black holes in AdS4 and their CFT duals\nby
Chiara Toldo (Ecole Polytechnique) as part of KIAS String Seminars\n\n\nAb
stract\nIn this talk I will review recent progress on the microstate count
ing for rotating black holes in Anti-de Sitter (AdS) spacetime. I will foc
us mostly on the gravitational part. I will review the known supersymmetri
c AdS solutions and I will describe how to construct two classes of new BP
S black holes in theories of four dimensional supergravity with uplift to
M-theory. I will describe their physical properties including their conser
ved charges and their entropy function. I will then review the state-of-th
e-art concerning their microstate counting via supersymmetric localization
.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nakwoo Kim (Kyung Hee University)
DTSTART;VALUE=DATE-TIME:20200601T080000Z
DTEND;VALUE=DATE-TIME:20200601T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/9
DESCRIPTION:Title: Updates on Precision Holography\nby Nakwoo Kim (Kyung Hee
University) as part of KIAS String Seminars\n\n\nAbstract\nWe study super
gravity BPS equations which correspond to mass-deformation of some represe
ntative AdS/CFT examples. The field theory of interest are N=4\, D=4 super
Yang-Mills\, the ABJM model in D=3\, and the Brandhuber-Oz fixed point in
D=5. For these gauge theories the free energy with mass terms for matter
multiplets is calculable in large-N limit using supersymmetric localizatio
n technique. We suggest a perturbative method to solve the supergravity eq
uations. For the dual of mass-deformed ABJM model we reproduce the known e
xact solutions. For the mass-deformed Brandhuber-Oz theory our method give
s the holographic free energy in analytic form. For N=2* theory our result
is in good agreement with the localization result. (based on 1902.00418)\
n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seyed Morteza Hosseini (IPMU)
DTSTART;VALUE=DATE-TIME:20200706T080000Z
DTEND;VALUE=DATE-TIME:20200706T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/10
DESCRIPTION:Title: Anomalies\, Black strings and the charged Cardy formula\
nby Seyed Morteza Hosseini (IPMU) as part of KIAS String Seminars\n\n\nAbs
tract\nWe derive the general anomaly polynomial for a class of two-dimensi
onal CFTs arising as twisted compactifications of a higher-dimensional the
ory on compact manifolds\, including the contribution of its isometries. W
e then use the result to perform a counting of microstates for dyonic rota
ting supersymmetric black strings in AdS(5) x S^5 and AdS(7) x S^4. We exp
licitly construct these solutions by uplifting a class of four-dimensional
rotating black holes. We provide a microscopic explanation of the entropy
of such black holes by using a charged version of the Cardy formula.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andy O'Bannon (U. of Southampton)
DTSTART;VALUE=DATE-TIME:20200713T080000Z
DTEND;VALUE=DATE-TIME:20200713T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/11
DESCRIPTION:Title: Central charges of two-dimensional boundaries and defects\nby Andy O'Bannon (U. of Southampton) as part of KIAS String Seminars\n\
n\nAbstract\nIn a 2d conformal field theory (CFT) the central charge is de
fined from the Virasoro algebra. Crucially\, the central charge obeys the
c-theorem\, a powerful\, universal\, non-perturbative constraint: the cent
ral charge must decrease under renormalization group flows. The central ch
arge appears in many other places too\, such as stress-tensor two-point fu
nctions\, thermal entropy\, entanglement entropy\, and so on. All of these
indicate that the central charge counts CFT degrees of freedom. However\,
what happens with a 2d boundary of a 3d CFT\, or a 2d conformal defect in
a higher-dimensional CFT? Generically in these cases no Virasoro algebra
is present. Can we still define a central charge? If so\, in what quantiti
es does it appear? Can we prove a c-theorem? These questions may be crucia
l for graphene with a boundary\, surface operators in gauge theory CFTs\,
and many other systems. In this talk I will summarize the state of the art
in this area\, including results for some example systems\, and open ques
tions.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Noppadol Mekareeya (Milano Bicocca)
DTSTART;VALUE=DATE-TIME:20200810T080000Z
DTEND;VALUE=DATE-TIME:20200810T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/12
DESCRIPTION:Title: Supersymmetry enhancement in the 3d S-fold theories\nby
Noppadol Mekareeya (Milano Bicocca) as part of KIAS String Seminars\n\n\nA
bstract\nA local SL(2\,Z) transformation on the Type IIB brane configurati
on gives rise to an interesting class of 3d superconformal field theories\
, known as the S-fold SCFTs. One of the interesting features of such a the
ory is that\, in general\, it does not admit a conventional Lagrangian des
cription. Nevertheless\, it can be described by a quiver diagram with a bu
ilding block being an SCFT known as the T(U(N)) theory. In this talk\, we
discuss various interesting properties of the S-fold theories\, including
supersymmetry enhancement in the infrared as well as several interesting d
ualities. This talk will have a different emphasis than previous talks wi
th the similar title and abstract.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sara Pasquetti (Milano Bicocca)
DTSTART;VALUE=DATE-TIME:20200803T080000Z
DTEND;VALUE=DATE-TIME:20200803T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/13
DESCRIPTION:Title: Free field correlators\, kernel functions and 4d mirror symm
etry\nby Sara Pasquetti (Milano Bicocca) as part of KIAS String Semina
rs\n\n\nAbstract\nI will present a family of quiver 4d N=1 theories which
present an interesting pattern of IR symmetry enhancement and are related
by a new type of IR dualities which are very similar to 3d N=4 mirror dua
lities.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Junya Yagi (Perimeter Institute)
DTSTART;VALUE=DATE-TIME:20200817T080000Z
DTEND;VALUE=DATE-TIME:20200817T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/14
DESCRIPTION:Title: Wilson-'t Hooft lines as transfer matrices\nby Junya Yag
i (Perimeter Institute) as part of KIAS String Seminars\n\n\nAbstract\nSup
ersymmetric gauge theories in four dimensions have various interrelated co
nnections to quantum integrable systems. I will present a new corresponden
ce which identifies Wilson-'t Hooft lines in N=2 circular quiver theories
with transfer matrices of trigonometric systems. I will explain how this
correspondence is related to Costello's 4d Chern-Simons theory and other s
imilar correspondences. This is based on my joint work with Kazunobu Maru
yoshi and Toshihiro Ota.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matti Jarvinen (APCTP)
DTSTART;VALUE=DATE-TIME:20200928T080000Z
DTEND;VALUE=DATE-TIME:20200928T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/15
DESCRIPTION:Title: Holographic Dense QCD and Neutron Stars\nby Matti Jarvin
en (APCTP) as part of KIAS String Seminars\n\n\nAbstract\nGauge/gravity du
ality can be used to study QCD at high densities and low temperatures wher
e many other theoretical tools do not work and uncertainties are therefore
large. I review recent progress on this topic\, including modeling of bot
h the nuclear and the quark matter phases\, which may appear in neutron st
ar cores and neutron star mergers. Combining predictions from gauge/gravit
y duality with state-of-the-art models of nuclear matter leads to a family
of feasible "hybrid" equations of state for cold QCD matter. I discuss ap
plications to analysis of isolated neutron stars\, to transport in dense q
uark matter\, and to simulations of binary neutron star mergers.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lavneet Janagal (KIAS)
DTSTART;VALUE=DATE-TIME:20201012T080000Z
DTEND;VALUE=DATE-TIME:20201012T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/16
DESCRIPTION:Title: CANCELLED\nby Lavneet Janagal (KIAS) as part of KIAS Str
ing Seminars\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthias Gaberdiel (ETH Zurich)
DTSTART;VALUE=DATE-TIME:20201102T080000Z
DTEND;VALUE=DATE-TIME:20201102T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/17
DESCRIPTION:Title: An exact AdS/CFT duality\nby Matthias Gaberdiel (ETH Zur
ich) as part of KIAS String Seminars\n\n\nAbstract\nString theory on AdS3
x S3 x T4 with one unit of NS-NS flux is argued to be exactly dual to the
symmetric orbifold of T4 in the large N limit. The string theory backgroun
d can be described in terms of a solvable world-sheet theory. This allows
one to compute the complete single-string spacetime spectrum and thereby d
emonstrate that it agrees with that of the symmetric orbifold of T4. Furth
ermore\, the structure of the symmetric orbifold correlators can be reprod
uced from the world-sheet perspective.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robert de Mello Koch (South China Normal U. and Witwatersrand U)
DTSTART;VALUE=DATE-TIME:20201123T080000Z
DTEND;VALUE=DATE-TIME:20201123T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/18
DESCRIPTION:Title: Why deep networks generalize\nby Robert de Mello Koch (S
outh China Normal U. and Witwatersrand U) as part of KIAS String Seminars\
n\n\nAbstract\nTraining a deep network involves applying an algorithm whic
h fixes the parameters of the network. The performance of the trained deep
network is evaluated by studying the trained network's performance on uns
een test data. The difference between how the network performs on the trai
ning data and on unseen data defines a generalization error. Networks that
perform as well on unseen data as they did on training data\, have a smal
l generalization error.\n\nWe have definite expectations for the size of t
he generalization error\, based essentially on common sense. If the traini
ng data set is much smaller than the number of parameters in the network\,
training can fit any data perfectly\, so that errors and noise are captur
ed during training. Typical deeps network applications use deep networks w
ith hundreds of millions of parameters\, trained using data sets with tens
of thousands of parameters. Clearly then\, we are squarely in the regime
of large generalization errors. Remarkably however\, for typical deep lear
ning applications\, the generalization error is small. This begs the quest
ion: why do deep nets generalize?\n\nIn this talk we develop parallels bet
ween deep learning and the renormalization group to explain why deep netwo
rks generalize.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christopher Herzog (King's College London)
DTSTART;VALUE=DATE-TIME:20201109T053000Z
DTEND;VALUE=DATE-TIME:20201109T063000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/19
DESCRIPTION:Title: Tractable models of boundary conformal field theory: The cas
e of O($N$) $\\phi^6$ theory in three dimensions\nby Christopher Herzo
g (King's College London) as part of KIAS String Seminars\n\n\nAbstract\nI
present a study of O($N$) $\\phi^6$ theory in three dimensions with a bou
ndary.\nIn the large $N$ limit\, the theory is approximately conformal. Tu
ning an approximately marginal coupling drives the theory into different p
hases. This model further allows a calculation of the boundary contributio
n to the anomaly in the trace of the stress tensor. Based on 2005.07863.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:R Loganayagam (ICTS-TIFR\, Bengaluru)
DTSTART;VALUE=DATE-TIME:20201116T080000Z
DTEND;VALUE=DATE-TIME:20201116T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/20
DESCRIPTION:Title: Interacting Hawking Radiation and Open QFTs\nby R Logana
yagam (ICTS-TIFR\, Bengaluru) as part of KIAS String Seminars\n\n\nAbstrac
t\nIn this talk\, I will outline some of the recent developments in AdS/CF
T which allow us to study open quantum field theories using holographic me
thods. More precisely\, I will consider a quantum field theory (the system
) coupled to a holographic field theory at finite temperature (the environ
ment). The aim here is to integrate out the holographic environment with a
n aim of obtaining an effective dynamics for the resulting open quantum fi
eld theory. This is done using semiclassical gravitational Schwinger-Keldy
sh saddle geometries obtained by complexifying black hole spacetimes. In
addition to shedding light on open quantum systems coupled to strongly co
rrelated thermal environments\, these results also capture both the dissip
ative physics of black hole quasinormal modes\, as well as that of the flu
ctuations encoded in outgoing Hawking quanta\, and interactions between th
em.\n\nThis talk will be based on https://arxiv.org/abs/2004.02888 as well
as some upcoming work.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gabriel Wong (Fudan University)
DTSTART;VALUE=DATE-TIME:20201130T080000Z
DTEND;VALUE=DATE-TIME:20201130T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/21
DESCRIPTION:Title: Entanglement entropy and edge modes in topological string th
eory\nby Gabriel Wong (Fudan University) as part of KIAS String Semina
rs\n\n\nAbstract\nThe Ryu Takayanagi formula identifies the area of bounda
ry anchored extremal surfaces in AdS with the entanglement entropy of the
boundary CFT. However the bulk microstate interpretation of the extremal a
rea remains mysterious. Progress along this direction requires understand
ing how to define entanglement entropy in the bulk closed string theory.
As a toy model for AdS/CFT\, we study the entanglement entropy of closed
strings in the topological A model in the context of Gopakumar Vafa duali
ty. We give a self consistent factorization of the closed string Hilbert
space which leads to string edge modes transforming under a q-deformed su
rface symmetry group. Compatibility with this symmetry requires a q-de
formed definition of entanglement entropy. Using the topological vertex
formalism\, we define the Hartle Hawking state for the resolved conifold
and compute its q-deformed entropy directly from the closed string reduced
density matrix. We find a match with a target space replica calculation
using the proposal of Susskind and Uglum. We then apply the Gopakumar V
afa duality to reproduce the closed string entropy from Chern Simons theo
ry using the un-deformed definition of entanglement entropy. Finally we
relate non local aspects of our factorization map to analogous phenomenon
recently found in JT gravity.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ofer Aharony (Weizmann)
DTSTART;VALUE=DATE-TIME:20201208T080000Z
DTEND;VALUE=DATE-TIME:20201208T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/22
DESCRIPTION:Title: A derivation of AdS/CFT for vector models\nby Ofer Aharo
ny (Weizmann) as part of KIAS String Seminars\n\n\nAbstract\nAfter discuss
ing what it means to derive the AdS/CFT correspondence\, I will describe o
ur attempts (in collaboration with Shai Chester and Erez Urbach\, 2011.063
28) to make this correspondence explicit in the simplest case of the O(N)
vector model. We explicitly rewrite the path integral for the free or crit
ical O(N) (or U(N)) bosonic vector models in d space-time dimensions as a
path integral over fields (including massless high-spin fields) living on
(d+1)-dimensional anti-de Sitter space. Inspired by de Mello Koch\, Jevick
i\, Suzuki and Yoon and earlier work\, we first rewrite the vector models
in terms of bi-local fields\, then expand these fields in eigenmodes of th
e conformal group\, and finally map these eigenmodes to those of fields on
anti-de Sitter space. Our results provide an explicit (non-local) action
for a high-spin theory on anti-de Sitter space\, which is presumably equiv
alent in the large N limit to Vasiliev's classical high-spin gravity theor
y (with some specific gauge-fixing to a fixed background)\, but which can
be used also for loop computations. Our mapping is explicit within the 1/N
expansion\, but in principle can be extended also to finite N theories\,
where extra constraints on products of bulk fields need to be taken into a
ccount.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Takuya Okuda (University of Tokyo)
DTSTART;VALUE=DATE-TIME:20201214T080000Z
DTEND;VALUE=DATE-TIME:20201214T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/23
DESCRIPTION:Title: Janus interface entropy and Calabi's diastasis in four-dimen
sional N=2 superconformal field theories\nby Takuya Okuda (University
of Tokyo) as part of KIAS String Seminars\n\n\nAbstract\nWe study the entr
opy associated with the Janus interface in a 4d N=2 superconformal field t
heory. With the entropy defined as the interface contribution to an entang
lement entropy we show\, under mild assumptions\, that the Janus interface
entropy is proportional to the geometric quantity called Calabi's diastas
is on the space of N=2 marginal couplings\, confirming an earlier conjectu
re by two of the authors and generalizing a similar result in two dimensio
ns. Our method is based on a CFT consideration that makes use of the Casin
i-Huerta-Myers conformal map from the flat space to the round sphere.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yi-Nan Wang (Oxford)
DTSTART;VALUE=DATE-TIME:20210111T080000Z
DTEND;VALUE=DATE-TIME:20210111T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/24
DESCRIPTION:Title: 5d and 4d SCFTs from canonical threefold singularities\n
by Yi-Nan Wang (Oxford) as part of KIAS String Seminars\n\n\nAbstract\nIn
this talk\, I am going to investigate pairs of SCFTs associated to a canon
ical threefold singularity\, which consists of: (1) a 5d N=1 SCFT from M-t
heory (2) a 4d N=2 SCFT from IIB superstring theory. Interestingly\, the C
oulomb and Higgs branches of these theories can be studied by the resoluti
on or deformation of the singularity\, and they are intertwined by 3d N=4
mirror symmetry. As the examples\, I am going to discuss Seiberg En theori
es and also various theories associated to terminal singularities. For the
latter case\, they seem to describe either a free theory or the discrete
gauging of a free theory.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pietro Longhi (ETH Zurich)
DTSTART;VALUE=DATE-TIME:20210201T080000Z
DTEND;VALUE=DATE-TIME:20210201T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/25
DESCRIPTION:Title: (Beyond) BPS counting with Exponential Networks\nby Piet
ro Longhi (ETH Zurich) as part of KIAS String Seminars\n\n\nAbstract\nThis
talk is an introductory overview of the framework of exponential networks
\, its applications to counting BPS states in M theory compactifications\,
and related problems in enumerative geometry. \nAfter reviewing the relev
ant background and motivations\, I will present the key definitions and sh
ow some applications. Time permitting\, I will discuss the relation to qui
vers and wall-crossing invariants\, and a recent application to BPS counti
ng on the local Hirzebruch surface F_0.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tadashi Okazaki (Durham)
DTSTART;VALUE=DATE-TIME:20210322T080000Z
DTEND;VALUE=DATE-TIME:20210322T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/26
DESCRIPTION:Title: Operator Algebras in 3d N=4 gauge theories and their applica
tions\nby Tadashi Okazaki (Durham) as part of KIAS String Seminars\n\n
\nAbstract\nThe algebras emerging from three-dimensional N=4 supersymmetri
c gauge theories allow for new approaches to quantum field theories\, incl
uding computations of physical observables and rigorous formulation of du
alities. I will discuss the algebraic formulas of sphere partition functio
ns and correlation functions in terms of the twisted traces over the Verma
modules of the quantized Coulomb and Higgs branch algebras based on my wo
rk 1911.11126 with Davide Gaiotto and stringent tests of dualities of half
-BPS boundary conditions via half-indices based on my works 1905.07425\, 2
010.13177.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Leopoldo A. Pando Zayas (Michigan)
DTSTART;VALUE=DATE-TIME:20210329T010000Z
DTEND;VALUE=DATE-TIME:20210329T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/27
DESCRIPTION:Title: AdS BH entropy and the Kerr/CFT correspondence\nby Leopo
ldo A. Pando Zayas (Michigan) as part of KIAS String Seminars\n\n\nAbstrac
t\nThe Bekenstein-Hawking entropy of asymptotically Anti-de-Sitter black h
oles in dimensions 4\, 5\, 6 and 7 has recently been given an statistical
interpretation in the context of the AdS/CFT correspondence. The explanati
ons provided make use of intricate knowledge of the dual field theories in
3\, 4\, 5 and 6 dimensions. It is expected on accounts of the renormaliza
tion flow paradigm that such a universal aspect as the Bekenstein-Hawking
entropy might admit an explanation solely based on low-energy dynamics. We
point that the Kerr/CFT correspondence realizes this expectation by provi
ding a unified statistical interpretation for the entropy of all black ho
les and discuss some of the implications of this state of affairs.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dan Xie (Tsinghua)
DTSTART;VALUE=DATE-TIME:20210315T080000Z
DTEND;VALUE=DATE-TIME:20210315T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/28
DESCRIPTION:Title: Mixed hodge module and N=2 Coulomb branch solution\nby D
an Xie (Tsinghua) as part of KIAS String Seminars\n\n\nAbstract\nSeiberg-W
itten (SW) geometry has been the key to understand the Coulomb branch of 4
d N=2 theories. While many SW geometries have been found\, the understandi
ng of Coulomb branch physics is still difficult due to following reasons:
a) The difficulty in extracting electric-magnetic charge and flavor charge
\; b) The difficulty in finding the physics at special vacua\; c) The diff
iculty of finding SW differential. We show that new mathematical structur
e called mixed hodge module will help us solve above problems.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diego Rodriguez Gomez (Oviedo)
DTSTART;VALUE=DATE-TIME:20210308T080000Z
DTEND;VALUE=DATE-TIME:20210308T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/29
DESCRIPTION:Title: Correlation functions in finite temperature CFT and black ho
le singularities\nby Diego Rodriguez Gomez (Oviedo) as part of KIAS St
ring Seminars\n\n\nAbstract\nWe compute thermal 2-point correlation functi
ons in the black brane AdS5 background dual to 4d CFT’s at finite temper
ature for operators of large scaling dimension. We find a formula that mat
ches the expected structure the OPE. It exhibits an exponentiation propert
y\, whose origin we explain. We also compute the first correction to the t
wo-point function due to graviton emission\, which encodes the time travel
to the black hole singularity.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ashoke Sen (Harish-Chandra Res. Inst.)
DTSTART;VALUE=DATE-TIME:20210323T053000Z
DTEND;VALUE=DATE-TIME:20210323T070000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/30
DESCRIPTION:Title: D-instanton amplitudes in string theory - Lecture 2/3\nb
y Ashoke Sen (Harish-Chandra Res. Inst.) as part of KIAS String Seminars\n
\n\nAbstract\nD-instantons give non-perturbative contribution to string th
eory amplitudes which can be computed using world-sheet techniques. Howeve
r the integrals that appear in this computation often have\ndivergences fr
om corners of the moduli spaces which cannot be tamed by the usual procedu
re of analytic continuation. We show how using insights from string field
theory we can extract finite unambiguous results from these apparently div
ergent integrals.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ashoke Sen (Harish-Chandra Res. Inst.)
DTSTART;VALUE=DATE-TIME:20210322T053000Z
DTEND;VALUE=DATE-TIME:20210322T070000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/31
DESCRIPTION:Title: D-instanton amplitudes in string theory - Lecture 1/3\nb
y Ashoke Sen (Harish-Chandra Res. Inst.) as part of KIAS String Seminars\n
\n\nAbstract\nD-instantons give non-perturbative contribution to string th
eory amplitudes which can be computed using world-sheet techniques. Howeve
r the integrals that appear in this computation often have\ndivergences fr
om corners of the moduli spaces which cannot be tamed by the usual procedu
re of analytic continuation. We show how using insights from string field
theory we can extract finite unambiguous results from these apparently div
ergent integrals.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ashoke Sen (Harish-Chandra Res. Inst.)
DTSTART;VALUE=DATE-TIME:20210324T053000Z
DTEND;VALUE=DATE-TIME:20210324T070000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/32
DESCRIPTION:Title: D-instanton amplitudes in string theory - Lecture 3/3\nb
y Ashoke Sen (Harish-Chandra Res. Inst.) as part of KIAS String Seminars\n
\n\nAbstract\nD-instantons give non-perturbative contribution to string th
eory amplitudes which can be computed using world-sheet techniques. Howeve
r the integrals that appear in this computation often have\ndivergences fr
om corners of the moduli spaces which cannot be tamed by the usual procedu
re of analytic continuation. We show how using insights from string field
theory we can extract finite unambiguous results from these apparently div
ergent integrals.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Per Kraus (UCLA)
DTSTART;VALUE=DATE-TIME:20210412T020000Z
DTEND;VALUE=DATE-TIME:20210412T030000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/33
DESCRIPTION:Title: 3d gravity in a box\nby Per Kraus (UCLA) as part of KIAS
String Seminars\n\n\nAbstract\nI will discuss recent work on the classica
l and quantum formulation of pure 3d gravity with Dirichlet boundary condi
tions. Working in the covariant phase space formalism I will show how to o
btain the classical Poisson bracket algebra of observables in this theory\
, and then discuss quantization\, comparing low order results to expectati
ons based on TTbar deformed CFTs.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Prem Kumar (Swansea University)
DTSTART;VALUE=DATE-TIME:20210510T080000Z
DTEND;VALUE=DATE-TIME:20210510T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/34
DESCRIPTION:Title: Islands and Hawking radiation correlations of evaporating bl
ack holes\nby Prem Kumar (Swansea University) as part of KIAS String S
eminars\n\n\nAbstract\nWe consider the effect of shockwaves on the entang
lement structure of black holes. We examine the correlations in generic
subsets of the Hawking radiation emitted by evaporating black holes follow
ing the shockwave insertion and find a zoo of competing island saddle poin
ts for the associated entanglement entropies. By computing the mutual info
rmation between early and late modes we establish long range correlations
in the Hawking radiation.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Davide Cassani (Padova)
DTSTART;VALUE=DATE-TIME:20210419T080000Z
DTEND;VALUE=DATE-TIME:20210419T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/35
DESCRIPTION:Title: Effective field theory for the 4d N=1 index on the second sh
eet\nby Davide Cassani (Padova) as part of KIAS String Seminars\n\n\nA
bstract\nThe counting of BPS states in four-dimensional N=1 theories has a
ttracted a lot of attention in recent years. A generating function (with s
igns) for this counting problem is the supersymmetric index. This has bran
ch cuts and hence several Cardy-like limits\, which are analogous to high-
temperature limits. Particularly interesting is the second sheet\, which h
as been shown to capture the microstates and phases of supersymmetric blac
k holes in AdS_5. The talk will present a manifestly supersymmetric 3d eff
ective field theory approach to the Cardy-like limit on the second sheet.
Due to the interaction between massless and massive modes\, the 3d theory
flows to a trivially gapped vacuum. I will describe how\, up to exponentia
lly small corrections\, the index is then completely characterized by a un
iversal\, finite series made of 3d local terms\, the supersymmetric Casimi
r energy and a very simple logarithmic term. These will be determined in p
art explicitly and in part conjecturally.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Monica Jinwoo Kang (KAIST)
DTSTART;VALUE=DATE-TIME:20210503T080000Z
DTEND;VALUE=DATE-TIME:20210503T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/36
DESCRIPTION:Title: 6d (1\,0) SCFTs on a torus and Class S\nby Monica Jinwoo
Kang (KAIST) as part of KIAS String Seminars\n\n\nAbstract\nIt has been a
constant framework to utilize geometric analysis via compactification to
study the strongly coupled regime of the lower-dimensional theories via hi
gher-dimensional theories. In particular\, I will present 4d N=2 superconf
ormal field theories (of class S) from two 6d origins: (1\,0) theory on a
torus and (2\,0) theory on a punctured Riemann surface. I will algorithmic
ally describe how to get the 4d data from 6d (1\,0) SCFTs via F-theory wit
h geometric-engineering and explain its physical significance.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jeff Murugan (University of Cape Town)
DTSTART;VALUE=DATE-TIME:20210426T080000Z
DTEND;VALUE=DATE-TIME:20210426T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/37
DESCRIPTION:Title: A 4-dimensional duality web\nby Jeff Murugan (University
of Cape Town) as part of KIAS String Seminars\n\n\nAbstract\nI will discu
ss the construction of a web of non-supersymmetric dualities in four space
time dimensions for theories with theta and Maxwell terms. Our constructio
n mirrors the recipe used in (2+1)-dimensions to demonstrate a similar dua
lity web for theories with Chern-Simons terms and points to a multi-dimens
ional duality web that connects low energy theories in 4-\, 3- and 2-space
time dimensions. Time permitting\, I will discuss some applications to the
physics of 3d topological insulators.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jeong-Hyuck Park (Sogang University)
DTSTART;VALUE=DATE-TIME:20210517T080000Z
DTEND;VALUE=DATE-TIME:20210517T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/38
DESCRIPTION:Title: String Theory and Non-Riemannian Geometry\nby Jeong-Hyuc
k Park (Sogang University) as part of KIAS String Seminars\n\n\nAbstract\n
Postulating O(D\,D) symmetry as the fundamental principle\, General Relati
vity including the Einstein equations can be unambiguously augmented to an
other pure gravity\, namely Double Field Theory. Formulated a priori in t
erms of O(D\,D) covariant variables\, Double Field Theory and also associ
ated doubled worldsheet action not only geometrize the whole closed strin
g massless sector which is conventionally Riemannian\, but also describe v
arious non-Riemannian geometries as novel string backgrounds.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francesco Benini (SISSA)
DTSTART;VALUE=DATE-TIME:20210531T080000Z
DTEND;VALUE=DATE-TIME:20210531T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/39
DESCRIPTION:Title: Superconformal Index and Gravitational Path Integral\nby
Francesco Benini (SISSA) as part of KIAS String Seminars\n\n\nAbstract\nA
dS/CFT provides a consistent non-perturbative definition of quantum\ngravi
ty in asymptotically AdS spacetimes. Black holes should\ncorrespond to ens
embles of states in the boundary field theory. By\nperforming a careful an
alysis of the superconformal index of 4d N=4\nSU(N) Super-Yang-Mills theor
y\, with the help of a Bethe Ansatz type\nformula\, we are able to exactly
reproduce the Bekenstein-Hawking\nentropy of BPS black holes in AdS5 x S5
. The large N limit exhibits\nmany competing contributions\, that we are a
ble to identify with\ncomplex saddles of the (putative) gravitational path
-integral. Along\nthe way we propose a necessary condition for complex sad
dles to\ncontribute\, based on the size of their non-perturbative correcti
ons.\nSuch a prescription exactly matches the field theory analysis.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rajesh Gopakumar (ICTS)
DTSTART;VALUE=DATE-TIME:20210622T080000Z
DTEND;VALUE=DATE-TIME:20210622T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/40
DESCRIPTION:Title: [Date Changed] The String dual to Free $\\mathcal{N}=4$ Supe
r Yang-Mills theory\nby Rajesh Gopakumar (ICTS) as part of KIAS String
Seminars\n\n\nAbstract\nIn this talk we will discuss a proposal for a wor
ldsheet description for the ${\\rm AdS}_5\\times {\\rm S}^5$ string theory
dual to large $N$\, free $\\mathcal{N}=4$ super Yang-Mills in four dimens
ions. The worldsheet theory is a natural generalisation of the twistorial
free sigma model for the tensionless string on ${\\rm AdS}_3\\times {\\rm
S}^3\\times \\mathbb{T}^4$. As in the case of ${\\rm AdS}_3$ the worldshe
et theory contains spectrally flowed representations. We propose that in e
ach such sector only a finite set of generalised zero modes (‘wedge mode
s’) are physical. We show that after imposing the appropriate residual g
auge conditions\, this worldsheet description reproduces precisely the spe
ctrum of the planar gauge theory. The resulting physical picture is a cova
riant version of the BMN light-cone string\, now with a finite number of t
wistorial string bit constituents of an essentially topological worldsheet
.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seung-Joo Lee (IBS)
DTSTART;VALUE=DATE-TIME:20210607T080000Z
DTEND;VALUE=DATE-TIME:20210607T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/41
DESCRIPTION:Title: Tensionless Strings and the Swampland in Four Dimensions
\nby Seung-Joo Lee (IBS) as part of KIAS String Seminars\n\n\nAbstract\nTh
e aim of this talk is to report on recent progress towards understanding h
ow string theory realizes general conjectures on the nature of quantum gra
vity\, focusing on four-dimensional theories with minimal supersymmetry. S
pecifically we will address two famous conjectures: the Distance Conjectur
e and the Weak Gravity Conjecture. The former claims that an infinite towe
r of states should become light near the boundary of the moduli space. Acc
ording to the Emergent String Conjecture\, this tower should correspond ei
ther to a Kaluza-Klein tower or to the excitation tower of a weakly couple
d critical string. We will first verify this within the framework of geome
tric F-theory compactifications\, by classifying infinite distance limits
in the Kahler moduli space and analyzing them including quantum correction
s. We will then argue that the string tower at weak coupling provides a su
blattice of particles fulfilling the Weak Gravity Conjecture\, at or away
from the strict infinities.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Julius Grimminger (Imperial College)
DTSTART;VALUE=DATE-TIME:20210524T080000Z
DTEND;VALUE=DATE-TIME:20210524T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/42
DESCRIPTION:Title: Branes\, Quivers\, and the affine Grassmannian\nby Juliu
s Grimminger (Imperial College) as part of KIAS String Seminars\n\n\nAbstr
act\nThe affine Grassmannian of a group G is an object from geometric repr
esentation theory. We will see that it arises quite naturally when studyin
g gauge theories with 8 supercharges and the brane systems they live on. W
e will begin by reviewing the notion of Hasse diagrams\, stratification an
d transverse slices for Coulomb branches of 3d N=4 quiver theories\, and h
ow this is captured by Kraft-Procesi transitions in the brane system. We w
ill then study the affine Grassmannian from this perspective\, starting wi
th the simplest possible one where G=SL(2\,C). We will then generalise to
higher ranks and other classical groups. If there is enough time\, excepti
onal groups will be addressed.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jie Gu (University of Geneva)
DTSTART;VALUE=DATE-TIME:20210621T080000Z
DTEND;VALUE=DATE-TIME:20210621T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/43
DESCRIPTION:Title: Resurgence and BPS invariants\nby Jie Gu (University of
Geneva) as part of KIAS String Seminars\n\n\nAbstract\nAsymptotic series a
re ubiquitous in physics. And the resurgence theory provides a powerful t
ool to study them. In particular the resurgence theory reveals that diffe
rent asymptotic series at different saddle points are related to each othe
r by Stokes automorphisms characterised by Stokes constants. We argue that
the Stokes constants can be treated as new invariants of the theories in
question\, and in some non-trivial examples they are integers and they can
be interpreted as counting of BPS states. We support this statement with
examples in Seiberg-Witten theory\, complex Chern-Simons theory\, and top
ological string theory. The topological string -- spectral theory (TS/ST)
correspondence plays an important in the last example.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rajesh Gopakumar (ICTS)
DTSTART;VALUE=DATE-TIME:20210608T050000Z
DTEND;VALUE=DATE-TIME:20210608T063000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/44
DESCRIPTION:Title: [KIAS Lecture Series] Lecture 1: Deriving the $AdS_3/CFT_2$
correspondence\nby Rajesh Gopakumar (ICTS) as part of KIAS String Semi
nars\n\n\nAbstract\nIn these lectures I will try to give an accessible int
roduction to a program to derive the AdS/CFT duality starting from the ten
sionless limit of the string theory. We will focus on the case of $AdS_3/C
FT_2$ where the tensionless string theory on $AdS_3 \\times S^3\\times T^4
$ has one unit of NS-NS flux and is dual to the free symmetric orbifold th
eory $(T^4)^N/S_N$ (in the large $N$ limit). The string theory in this lim
it is described by a twistorial free field sigma model. We will discuss h
ow the perturbative string spectrum matches with those of the single cycl
e operators on the orbifold. Then we go on to argue why correlation functi
ons of physical operators manifestly match with those of the orbifold theo
ry. This follows from a subtle but crucial property of localisation of the
string correlators on the moduli space. Time permitting I will also discu
ss some implications of the duality for the physics of black holes in this
background.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rajesh Gopakumar (ICTS)
DTSTART;VALUE=DATE-TIME:20210609T050000Z
DTEND;VALUE=DATE-TIME:20210609T063000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/45
DESCRIPTION:Title: [KIAS Lecture Series] Lecture 2: Deriving the $AdS_3/CFT_2$
correspondence\nby Rajesh Gopakumar (ICTS) as part of KIAS String Semi
nars\n\n\nAbstract\nIn these lectures I will try to give an accessible int
roduction to a program to derive the AdS/CFT duality starting from the ten
sionless limit of the string theory. We will focus on the case of $AdS_3/C
FT_2$ where the tensionless string theory on $AdS_3 \\times S^3\\times T^4
$ has one unit of NS-NS flux and is dual to the free symmetric orbifold th
eory $(T^4)^N/S_N$ (in the large $N$ limit). The string theory in this lim
it is described by a twistorial free field sigma model. We will discuss h
ow the perturbative string spectrum matches with those of the single cycl
e operators on the orbifold. Then we go on to argue why correlation functi
ons of physical operators manifestly match with those of the orbifold theo
ry. This follows from a subtle but crucial property of localisation of the
string correlators on the moduli space. Time permitting I will also discu
ss some implications of the duality for the physics of black holes in this
background.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rajesh Gopakumar (ICTS)
DTSTART;VALUE=DATE-TIME:20210610T050000Z
DTEND;VALUE=DATE-TIME:20210610T063000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/46
DESCRIPTION:Title: [KIAS Lecture Series] Lecture 3: Deriving the $AdS_3/CFT_2$
correspondence\nby Rajesh Gopakumar (ICTS) as part of KIAS String Semi
nars\n\n\nAbstract\nIn these lectures I will try to give an accessible int
roduction to a program to derive the AdS/CFT duality starting from the ten
sionless limit of the string theory. We will focus on the case of $AdS_3/C
FT_2$ where the tensionless string theory on $AdS_3 \\times S^3\\times T^4
$ has one unit of NS-NS flux and is dual to the free symmetric orbifold th
eory $(T^4)^N/S_N$ (in the large $N$ limit). The string theory in this lim
it is described by a twistorial free field sigma model. We will discuss h
ow the perturbative string spectrum matches with those of the single cycl
e operators on the orbifold. Then we go on to argue why correlation functi
ons of physical operators manifestly match with those of the orbifold theo
ry. This follows from a subtle but crucial property of localisation of the
string correlators on the moduli space. Time permitting I will also discu
ss some implications of the duality for the physics of black holes in this
background.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Minsung Kim (POSTECH)
DTSTART;VALUE=DATE-TIME:20210628T080000Z
DTEND;VALUE=DATE-TIME:20210628T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/47
DESCRIPTION:Title: 5d/6d Wilson loops from blowups\nby Minsung Kim (POSTECH
) as part of KIAS String Seminars\n\n\nAbstract\nRecently\, BPS spectra of
large class of 5d and 6d supersymmetric quantum field theories are comput
ed via blowup equation. We generalize the blowup formula to calculate the
partition function of 5d/6d field theories on Omega-background in presence
of Wilson loop/Wilson surface operators. We test this approach by calcula
ting Wilson loop partition functions in various 5d/6d field theories and c
omparing them with known results and expected dualities.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yutaka Yoshida (Tokyo Inst. of Technology)
DTSTART;VALUE=DATE-TIME:20210712T080000Z
DTEND;VALUE=DATE-TIME:20210712T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/48
DESCRIPTION:Title: Monopole bubbling and BPS 't Hooft operators in three\, four
and five dimensions\nby Yutaka Yoshida (Tokyo Inst. of Technology) as
part of KIAS String Seminars\n\n\nAbstract\nWe evaluate the vacuum expect
ation values of half-BPS 't Hooft operators in supersymmetric gauge theori
es with eight supercharges in three\, four\, and five dimensions in terms
of supersymmetric localization. In localization formulas\, there exist non
-perturbative contributions from the moduli of Dirac monopoles screened by
't Hooft-Polyakov monopoles\, called monopole bubbling effects (a.k.a. mo
nopole screening effects). By introducing orientifolds\, we generalize the
brane construction of monopole bubbling effects for SU(N) gauge theories
to SO(N) and USp(N) gauge theories.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Junho Hong (KU Leuven)
DTSTART;VALUE=DATE-TIME:20210927T080000Z
DTEND;VALUE=DATE-TIME:20210927T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/49
DESCRIPTION:Title: The topologically twisted index of N=4 SU(N) SYM theory and
a black hole Farey tail\nby Junho Hong (KU Leuven) as part of KIAS Str
ing Seminars\n\n\nAbstract\nIn this talk\, we investigate the large-N asym
ptotics of the topologically twisted index of N=4 SU(N) Super-Yang-Mills (
SYM) theory on T2×S2 and provide its holographic interpretation based on
the black hole Farey tail. In the field theory side\, we use the Bethe-Ans
atz (BA) formula\, which gives the twisted index of N=4 SYM theory as a di
screte sum over Bethe vacua\, to compute the large-N asymptotics of the tw
isted index. In a dual N=2 gauged STU model\, we construct a family of 5d
extremal solutions uplifted from the 3d black hole Farey tail\, and comput
e the regularized on-shell actions. The gravitational partition function g
iven in terms of these regularized on-shell actions is then compared with
a canonical partition function derived from the twisted index by the inver
se Laplace transform\, in the large-N limit. This extends the previous mic
rostate counting of an AdS5 black string by the twisted index and thereby
improves holographic understanding of the twisted index. Lastly\, we discu
ss future research directions.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matteo Bertolini (SISSA\, Trieste)
DTSTART;VALUE=DATE-TIME:20210915T080000Z
DTEND;VALUE=DATE-TIME:20210915T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/50
DESCRIPTION:Title: The Octagon and the Non-Supersymmetric String Landscape\
nby Matteo Bertolini (SISSA\, Trieste) as part of KIAS String Seminars\n\n
\nAbstract\nA long standing open question in the context of the gauge/grav
ity correspondence - more specifically in models of D-branes at Calabi-Yau
singularities - regards the possibility of describing holographically su
persymmetric gauge theories that dynamically break supersymmetry in stable
vacua. In this talk I will present an orientifold of a Calabi-Yau singu
larity\, the Octagon\, which admits configurations of D-branes with this p
roperty. This model represents the first such instance within the gauge/gr
avity duality and may find interesting applications therein. I will also e
xplain to what extent this result might be relevant for the string theory
landscape and the swampland program.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christopher Couzens (Utrecht University)
DTSTART;VALUE=DATE-TIME:20210913T080000Z
DTEND;VALUE=DATE-TIME:20210913T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/51
DESCRIPTION:Title: Black string near-horizons\, 2d quiver SCFTs and fractional
branes\nby Christopher Couzens (Utrecht University) as part of KIAS St
ring Seminars\n\n\nAbstract\nWe will discuss a recently classified class o
f (0\,4) AdS3 solutions in massless type IIA supergravity and their dual C
FTs. The solutions depend on solving a Laplace-like equation with a flux s
ource term. We will focus on a solution of this master equation where the
flux source term arises due to the presence of fractional branes preservin
g conformality. We give a candidate dual quiver 2d CFT by studying the bra
ne construction and the quantized strings of the setup.\nThis talk is base
d on recent work with Y. Lozano\, N. Petri\, and S. Vandoren.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lorenzo Di Pietro (Trieste University)
DTSTART;VALUE=DATE-TIME:20211018T080000Z
DTEND;VALUE=DATE-TIME:20211018T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/52
DESCRIPTION:Title: 5d gauge theories from the epsilon expansion\nby Lorenzo
Di Pietro (Trieste University) as part of KIAS String Seminars\n\n\nAbstr
act\nThe seminar is based on: https://arxiv.org/abs/2107.00342. I will dis
cuss new evidence -from the 4+epsilon expansion- of the existence of inter
acting CFTs in 5d that provide UV completions of non-abelian gauge theorie
s. The method used is Padé-Borel resummation and extrapolation of the fiv
e-loop pertubative results.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Irene Valenzuela (Harvard University)
DTSTART;VALUE=DATE-TIME:20211026T010000Z
DTEND;VALUE=DATE-TIME:20211026T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/53
DESCRIPTION:Title: Non-Invertible Global Symmetries and Completeness of the Spe
ctrum in the Swampland Program\nby Irene Valenzuela (Harvard Universit
y) as part of KIAS String Seminars\n\n\nAbstract\nIt is widely believed th
at consistent theories of quantum gravity satisfy two basic kinematic cons
traints: they are free from any global symmetry\, and they contain a compl
ete spectrum of gauge charges. For compact\, abelian gauge groups\, comple
teness follows from the absence of a 1-form global symmetry. However\, thi
s correspondence breaks down for more general gauge groups\, where the bre
aking of the 1-form symmetry is insufficient to guarantee a complete spect
rum. We show that the correspondence may be restored by broadening our not
ion of symmetry to include non-invertible topological operators\, and prov
e that their absence is sufficient to guarantee a complete spectrum for an
y compact\, possibly disconnected gauge group. In addition\, we prove an a
nalogous statement regarding the completeness of twist vortices: codimensi
on-2 objects defined by a discrete holonomy around their worldvolume\, suc
h as cosmic strings in four dimensions. I will also discuss how this corre
spondence is modified in more general contexts\, including e.g. Chern-Simo
ns terms.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Miguel Montero (Harvard University)
DTSTART;VALUE=DATE-TIME:20211005T040000Z
DTEND;VALUE=DATE-TIME:20211005T050000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/54
DESCRIPTION:Title: The anomaly that was not meant IIB\nby Miguel Montero (H
arvard University) as part of KIAS String Seminars\n\n\nAbstract\nType IIB
supergravity famously has a discrete duality group\, which is an exact sy
mmetry of the full type IIB string theory. This symmetry has potential qua
ntum anomalies\, which could render the theory inconsistent. In this talk
I will describe how we computed these anomalies in recent work\, and show
they are nonvanishing\, but remarkably\, they can be canceled by a subtle
modification of the IIB Chern-Simons term in what amounts to a new variant
of the Green-Schwarz mechanism. This only happens because of some cancell
ations that depend on the precise details of the IIB supergravity spectrum
. I will also describe alternative ways to cancel this anomaly\, presentin
g variant versions of IIB string theory which have the same IIB supergravi
ty as the low-energy limit\, but which differ at the nonperturbative level
. These theories may or may not be in the Swampland.\n\n*Please note the u
nusual time of the seminar -comment added by organizer\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Murat Kologlu (Oxford)
DTSTART;VALUE=DATE-TIME:20211101T080000Z
DTEND;VALUE=DATE-TIME:20211101T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/55
DESCRIPTION:Title: Factorization in Quantum Gravity and Supersymmetry\nby M
urat Kologlu (Oxford) as part of KIAS String Seminars\n\n\nAbstract\nOne o
f the lasting puzzles in quantum gravity is whether the holographic descri
ption of a gravitational system is a single quantum mechanical theory or t
he disorder average of many. In the latter case\, multiple copies of bound
ary observables do not factorize into a product\, but rather have higher m
oments. These correlations are interpreted in the bulk as due to geometrie
s involving spacetime wormholes which connect disjoint boundaries. \n\nI w
ill talk about the question of factorization and the role of wormholes for
supersymmetric observables\, specifically the supersymmetric index. Worki
ng with the Euclidean gravitational path integral\, we will start with a b
ulk prescription for computing the supersymmetric index\, which agrees wit
h the usual boundary definition. Concretely\, we will focus on the setting
of charged black holes in asymptotically flat four-dimensional N=2 ungaug
ed supergravity. In this case\, the gravitational index path integral has
an infinite family of Kerr-Newman classical saddles with different angular
velocities. However\, fermionic zero-mode fluctuations annihilate the con
tribution of each saddle except for a single BPS one which yields the expe
cted value of the index. We will then turn to non-perturbative corrections
involving spacetime wormholes\, and show that fermionic zero modes are pr
esent for all such geometries\, making their contributions vanish. This me
chanism works for both single- and multi-boundary path integrals. In parti
cular\, only disconnected geometries without wormholes contribute to the i
ndex path integral\, and the factorization puzzle that plagues the black h
ole partition function is resolved for the supersymmetric index. We will a
lso classify all other single-centered geometries that yield non-perturbat
ive contributions to the gravitational index of each boundary. Finally\, w
e will discuss implications and expectations for factorization and the sta
tus of supersymmetric ensembles in AdS/CFT in further generality. Talk bas
ed on [2107.09062] with Luca Iliesiu and Joaquin Turiaci.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nathan Benjamin (Caltech)
DTSTART;VALUE=DATE-TIME:20211012T010000Z
DTEND;VALUE=DATE-TIME:20211012T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/56
DESCRIPTION:Title: Harmonic analysis of 2d CFT partition functions\nby Nath
an Benjamin (Caltech) as part of KIAS String Seminars\n\n\nAbstract\nI wil
l discuss applying the theory of harmonic analysis on the fundamental doma
in of SL(2\,Z) to partition functions of 2d conformal field theories. As a
n application I will decompose the partition function of c free bosons on
a Narain lattice into eigenfunctions of the Laplacians of worldsheet modul
i space H/SL(2\,Z) and of target space moduli space O(c\,c\;Z)\\O(c\,c\;R)
/O(c)xO(c). This decomposition will make certain properties of Narain theo
ries including their ensemble averages manifest. I will also discuss apply
ing harmonic analysis to a general irrational 2d CFT and its connection wi
th gravity in AdS3. I will prove that the primary spectrum of any 2d CFT i
s fully determined by a certain subset of degeneracies. \n\n*Please be aw
are of the unusual date/time of the talk - comment added by organizer\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yosuke Imamura (Tokyo Inst. Tech.)
DTSTART;VALUE=DATE-TIME:20211115T070000Z
DTEND;VALUE=DATE-TIME:20211115T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/57
DESCRIPTION:Title: Finite-N superconformal index via the AdS/CFT correspondence
\nby Yosuke Imamura (Tokyo Inst. Tech.) as part of KIAS String Seminar
s\n\n\nAbstract\nWe propose a prescription to calculate the superconformal
index of the N=4 U(N) supersymmetric Yang-Mills theory\nwith finite N on
the AdS side. The finite N corrections are included as contributions of D3
-branes wrapped around\nthree-cycles in S5\, which are calculated as the i
ndex of the gauge theories realized on the wrapped branes.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andreas Karch (U. Texas\, Austin)
DTSTART;VALUE=DATE-TIME:20211210T010000Z
DTEND;VALUE=DATE-TIME:20211210T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/59
DESCRIPTION:Title: Exploring continuum quantum field theories of fracton order<
/a>\nby Andreas Karch (U. Texas\, Austin) as part of KIAS String Seminars\
n\n\nAbstract\nRecently discovered solvable lattice models\, known as frac
tons\, have\nforced us to rethink the very basic question of what a quantu
m field\ntheory is. In order to describe the continuum limit of fracton la
ttice\nmodels\, novel quantum field theories had to be written down that g
o\nbeyond what textbooks taught us\, exhibiting unusual features such as\n
subsystem symmetries\, UV sensitivity of IR quantities\, and broken\nrotat
ion invariance. This talk will describe several explorations of the\ninter
esting new properties these unusual field theories exhibit.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Haowu Wang (IBS CGP\, Pohang)
DTSTART;VALUE=DATE-TIME:20211116T070000Z
DTEND;VALUE=DATE-TIME:20211116T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/60
DESCRIPTION:Title: Recent results on Jacobi forms of lattice index\nby Haow
u Wang (IBS CGP\, Pohang) as part of KIAS String Seminars\n\n\nAbstract\nI
n 1985 Eichler and Zagier introduced the theory of Jacobi forms. Such form
s are holomorphic functions which are modular under SL(2\,Z) in the first
variable and quasi-periodic in the second variable. Later\, the Jacobi for
m of lattice index was defined by replacing the second variable with many
variables associated with a positive-definite lattice. Jacobi forms are an
elegant intermediate between different types of modular forms and have ma
ny applications in mathematics and physics. In this talk\, I will give a b
rief introduction to this theory and present some recent results. (1) In
1992 Wirthmüller proved that for any irreducible root system not of type
E_8 the algebra of weak Jacobi forms invariant under the Weyl group is a p
olynomial algebra. I will define the Jacobian of Jacobi forms and present
an automorphic proof of Wirthmüller's theorem. (2) Weyl invariant weak Ja
cobi forms for the exceptional root system E_8 appear in E-string theory.
I will prove several conjectures proposed by some physicists. This gives
a clear picture of the (non-free) algebra of such Jacobi forms. (3) I will
talk about the algebra of weak Jacobi forms for lattices of rank 2. Thi
s talk is based on joint works with Brandon Williams and with Kaiwen Sun.\
n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuji Hirono (APCTP)
DTSTART;VALUE=DATE-TIME:20211206T070000Z
DTEND;VALUE=DATE-TIME:20211206T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/61
DESCRIPTION:Title: Counting Nambu-Goldstone modes of higher-form global symmetr
ies\nby Yuji Hirono (APCTP) as part of KIAS String Seminars\n\n\nAbstr
act\nWhen continuous symmetries are spontaneously broken\, there appear\ng
apless modes called Nambu-Goldstone (NG) modes. Due to their gapless\nnatu
re\, they are important degrees of freedom at low energies.\nRecently\, a
generalized kind of symmetries\, called higher-form\nsymmetries\, have bee
n discussed\, whose charged objects are extended.\nThe analogue of the NG
theorem exists\, and photons can be regarded as\nNG modes for a spontaneou
sly broken higher-form symmetry.\nIn this talk\, I will discuss how to cou
nt the number of NG modes\nassociated with spontaneously broken symmetries
that can include\nhigher-form ones [1]. I will give a formula for the num
ber of NG\nmodes\, which is also applicable for systems without Lorentz\ni
nvariance.\n\nReference:\n[1] Y. Hidaka\, Y. Hirono\, R. Yokokura\, Phys.
Rev. Lett. 126\, 071601 (2021). [arXiv:2007.15901]\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hidenori Fukaya (Osaka University)
DTSTART;VALUE=DATE-TIME:20211220T070000Z
DTEND;VALUE=DATE-TIME:20211220T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/62
DESCRIPTION:Title: A physicist-friendly reformulation of the Atiyah-Patodi-Sing
er index\nby Hidenori Fukaya (Osaka University) as part of KIAS String
Seminars\n\n\nAbstract\nThe Atiyah-Singer index theorem on a closed manif
old is well understood and appreciated in physics. On the other hand\, the
Atiyah-Patodi-Singer index\, which is an extension to a manifold with bou
ndary\, is physicist-unfriendly\, in that it is formulated with a nonlocal
boundary condition. Recently we proved that the same index as APS is obta
ined from the domain-wall fermion Dirac operator. Our theorem indicates th
at the index can be expressed without any nonlocal conditions\, in such a
physicist-friendly way that application to the lattice gauge theory is str
aightforward. The domain-wall fermion provides a natural mathematical foun
dation for understanding the bulk-edge correspondence of the anomaly inflo
w.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/62/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jie Gu (Southeastern University of China)
DTSTART;VALUE=DATE-TIME:20211227T070000Z
DTEND;VALUE=DATE-TIME:20211227T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/63
DESCRIPTION:Title: Resurgent structure in Chern-Simons theory\nby Jie Gu (S
outheastern University of China) as part of KIAS String Seminars\n\n\nAbst
ract\nThe resurgence theory is a powerful technique to analyse asymptotic
series that arise in physics. We use the resurgence theory to study the Ch
ern-Simons theory with gauge group $\\mf{sl}_2$ on knot complement. We com
pute the Stokes automorphisms that relate the asymptotic series in the the
ory\, including the one from the trivial flat connection. We find surprisi
ng connection with BPS counting in 3d SCFT. We also construct a new state
integral from which all asymptotic series\, including the one for trivial
connection\, can be derived.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yifan Wang (New York University)
DTSTART;VALUE=DATE-TIME:20220125T010000Z
DTEND;VALUE=DATE-TIME:20220125T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/64
DESCRIPTION:Title: Bootstrapping Boundaries and Branes\nby Yifan Wang (New
York University) as part of KIAS String Seminars\n\n\nAbstract\nThe study
of conformal boundary conditions for two-dimensional conformal field theor
ies (CFTs) has a long history\, ranging from the description of impurities
in one-dimensional quantum chains to the formulation of D-branes in strin
g theory. Nevertheless\, the landscape of conformal boundaries is largely
unknown\, including in rational CFTs\, where the local operator data is co
mpletely determined. We initiate a systematic bootstrap study of conformal
boundaries in 2d CFTs by investigating the bootstrap equation that arises
from the open-closed consistency condition of the annulus partition funct
ion with identical boundaries. We find that this deceivingly simple bootst
rap equation\, when combined with unitarity\, leads to surprisingly strong
constraints on admissible boundary states. In particular\, we derive univ
ersal bounds on the tension (boundary entropy) of stable boundary conditio
ns\, which provide a rigorous diagnostic for potential D-brane decays. We
also find unique solutions to the bootstrap problem of stable branes in a
number of rational CFTs. Along the way\, we observe a curious connection b
etween the annulus bootstrap and the sphere packing problem\, which is a n
atural extension of previous work on the modular bootstrap. We also derive
bounds on the boundary entropy at large central charge. These potentially
have implications for end-of-the-world branes in pure gravity on AdS3.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuya Kusuki (Caltech)
DTSTART;VALUE=DATE-TIME:20220222T010000Z
DTEND;VALUE=DATE-TIME:20220222T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/65
DESCRIPTION:Title: Analytic Bootstrap in 2D Boundary Conformal Field Theory
\nby Yuya Kusuki (Caltech) as part of KIAS String Seminars\n\n\nAbstract\n
Recently\, boundary conformal field theories (BCFTs) have attracted much a
ttention in the context of quantum gravity. This is because a BCFT can be
dual to gravity coupled to a heat bath CFT\, known as the island model. On
this background\, it would be interesting to explore the duality between
the boundary and the braneworld. \nHowever\, this seems to be a challengin
g problem. The reason is because although there has been much study of rat
ional BCFTs\, there has been comparatively little study of irrational BCFT
s\, and irrational BCFTs are expected to be the boundary duals of the bran
eworlds. For this reason\, we explore properties of boundary ingredients:
the boundary primary spectrum\, the boundary-boundary-boundary OPE coeffic
ients and the bulk-boundary OPE coefficients. For this purpose\, the confo
rmal bootstrap is extremely useful. This is the first step in providing an
understanding of BCFTs in the context of braneworld holography by using t
he conformal bootstrap. The techniques developed in this paper may be usef
ul for further investigation of irrational BCFTs.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Paul-Konstantin Oehlmann (Uppsala University)
DTSTART;VALUE=DATE-TIME:20220221T080000Z
DTEND;VALUE=DATE-TIME:20220221T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/66
DESCRIPTION:Title: Twisted Affine Algebras in F/M-theory\nby Paul-Konstanti
n Oehlmann (Uppsala University) as part of KIAS String Seminars\n\n\nAbstr
act\nIn this talk we discuss the geometry and physics of M/F-theory compac
tifications on torus fibered Calabi-Yau threefolds that lack a section. Su
ch geometries admit some striking novel features that are not present when
the torus fiber admits a global section: \nThe absence of a section allow
s for generalized monodromies that act on the affine extension of ADE fibe
rs\, leading to twisted affine algebras in M-theory. We discuss the effect
of such foldings and their geometry in detail and track them through a ch
ain of conifold transitions. This allows us to explain the twisted affine
algebras as the results of a 5D Higgsing\, where the representations have
non-trivial charges under the KK U(1) which relates the theory to 6D F-the
ory.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/66/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yiwen Pan (SYSU\, Guangzhou)
DTSTART;VALUE=DATE-TIME:20220214T070000Z
DTEND;VALUE=DATE-TIME:20220214T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/67
DESCRIPTION:Title: Exact Schur Index in Closed Form\nby Yiwen Pan (SYSU\, G
uangzhou) as part of KIAS String Seminars\n\n\nAbstract\nThe Schur limit o
f the 4d N=2 superconformal index encodes rich information of the SCFT\, a
nd it also plays a central role in the SCFT/VOA correspondence as it coinc
ides with the character of the associated VOA. There have been several way
s to compute this quantity\, where it is written as a contour integral\, o
r an infinite sum of group characters\, or simply a q-series. In this talk
we propose for Lagrangian theories an elementary approach to further comp
ute the contour integral form of the index and the final result takes the
form of a finite sum of products of the well-known Eisenstein series. In p
articular\, we derive a compact formula for the flavored Schur index of al
l class-S theories of type a_1\, and conjecture simple closed-form for the
unflavor index of all N=4 SYM theories with SU(N) gauge groups. We also d
iscuss some applications to the non-Lagrangian Schur index\, index with no
n-local operators and modularity.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oleg Chalykh (University of Leeds)
DTSTART;VALUE=DATE-TIME:20220523T080000Z
DTEND;VALUE=DATE-TIME:20220523T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/68
DESCRIPTION:Title: Twisted Ruijsenaars models\nby Oleg Chalykh (University
of Leeds) as part of KIAS String Seminars\n\n\nAbstract\nThe quantum Ruijs
enaars model is a q-analogue of the Calogero—Moser model\, described by
n commuting partial difference operators (quantum hamiltonians) h_1\, …\
, h_n. Its trigonometric variant is closely related to Macdonald polynomia
ls and DAHAs. It turns out that for each natural number \\ell>1\, there ex
ists an integrable system whose quantum hamiltonians look\, loosely speaki
ng\, as the \\ell-th powers of h_1\, …\, h_n. I will discuss several way
s of arriving at this generalisation. In the elliptic case\, the deformati
on parameter (“twisting”) is an arbitrary \\ell-torsion point c on the
underlying elliptic curve\; when c=0 one gets precisely the \\ell-th powe
rs of h_1\, …\, h_n. The construction works for all root systems\, inclu
ding the Van Diejen's system (BC_n case) - the existence of such a twisted
version of the Van Diejen's system was previously conjectured by Eric Rai
ns.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theodore D. Brennan (U. Chicago)
DTSTART;VALUE=DATE-TIME:20220315T010000Z
DTEND;VALUE=DATE-TIME:20220315T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/69
DESCRIPTION:Title: Callan Rubakov Effect and Higher Charge Monopoles\nby Th
eodore D. Brennan (U. Chicago) as part of KIAS String Seminars\n\n\nAbstra
ct\nIn this talk we will discuss the interaction between magnetic monopole
s and massless fermions. In the 1980's Callan and Rubakov showed that in t
he simplest example and that fermion-monopole interactions catalyze proton
decay in GUT completions of the standard model. Here we will explain how
fermions in general representations interact with general spherically symm
etric monopoles and classify the types of symmetries that are broken: glob
al symmetries with ABJ-type anomalies.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/69/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Du Pei (Harvard CMSA)
DTSTART;VALUE=DATE-TIME:20220329T010000Z
DTEND;VALUE=DATE-TIME:20220329T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/70
DESCRIPTION:Title: Holomorphic CFTs and topological modular forms\nby Du Pe
i (Harvard CMSA) as part of KIAS String Seminars\n\n\nAbstract\nThe theory
of topological modular forms leads to many interesting constraints and pr
edictions for two-dimensional quantum field theories. In this talk\, I wil
l show that a conjecture by Segal\, Stolz and Teichner requires the consta
nt term of the partition function of a bosonic holomorphic CFTs to be divi
sible by specific integers determined by the central charge. We verify thi
s constraint in large classes of physical examples\, and rule out the exis
tence of an infinite set of "extremal CFTs"\, including those with central
charges c = 48\, 72\, 96 and 120.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/70/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sung-Soo Kim (UESTC\, Chengdu)
DTSTART;VALUE=DATE-TIME:20220328T070000Z
DTEND;VALUE=DATE-TIME:20220328T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/71
DESCRIPTION:Title: 6d Seiberg-Witten curves from 5-brane webs\nby Sung-Soo
Kim (UESTC\, Chengdu) as part of KIAS String Seminars\n\n\nAbstract\nIn th
is talk\, we discuss the construction of the Seiberg-Witten (SW) curves ba
sed on Type IIB 5-brane webs. After reviewing the construction for SW curv
es for 5d supersymmetric gauge theories\, we discuss how to generalize it
to 6d superconformal theories which can be realized on a 5-brane webs with
periodic direction. In particular\, we construct the SW curve for 6d E-st
ring theory using a 5-brane web with two O5-planes. In fact\, the E-string
SW curve was first constructed by Eguchi and Sakai which is rather compli
cated. Our expression is\, however\, much simpler than the Eguchi and Saka
i’s one. We discuss equivalence between our curve and the Eguchi and Sak
ai. Finally we further generalize our construction of the SW curves to 6d
little string theories.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/71/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hee-Joong Chung (Jeju National University)
DTSTART;VALUE=DATE-TIME:20220224T070000Z
DTEND;VALUE=DATE-TIME:20220224T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/72
DESCRIPTION:Title: BPS Invariants for a Knot in Seifert Manifolds\nby Hee-J
oong Chung (Jeju National University) as part of KIAS String Seminars\n\n\
nAbstract\nIn this talk\, we discuss homological blocks for a knot in Seif
ert manifolds obtained from the Chern-Simons partition function with a Wil
son loop operator when the gauge group is SU(N). From the expectation valu
e of the Wilson loop operator\, we calculate the homological blocks by ana
lytically continuing the Chern-Simons level with a given representation. W
e also obtain homological blocks with the analytically continued level and
representation for a knot in the Seifert integer homology spheres.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/72/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kanghoon Lee (APCTP)
DTSTART;VALUE=DATE-TIME:20220314T070000Z
DTEND;VALUE=DATE-TIME:20220314T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/73
DESCRIPTION:Title: QFT from Recursions\nby Kanghoon Lee (APCTP) as part of
KIAS String Seminars\n\n\nAbstract\nWe discuss off-shell recursion relatio
ns for arbitrary loop-level scattering amplitudes beyond the conventional
tree-level recursion relations. We define a quantum perturbiner expansion
that includes loop corrections from the quantum effective action formalism
. Instead of using the classical equations of motion in the conventional
perturbiner method\, we exploit the Dyson–Schwinger equation to derive t
he quantum off-shell recursion relation. Furthermore\, we construct the re
cursions for computing loop-level correlation functions by replacing the c
hoice of the external source.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/73/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Byoungjoon Ahn (GIST)
DTSTART;VALUE=DATE-TIME:20220418T070000Z
DTEND;VALUE=DATE-TIME:20220418T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/74
DESCRIPTION:Title: Holographic teleportation and traversable wormholes\nby
Byoungjoon Ahn (GIST) as part of KIAS String Seminars\n\n\nAbstract\nIn ge
neral\, the non-traversability of wormholes is a consequence of the Averag
e Null Energy Condition (ANEC). Gao\, Jafferis and Wall (GJW) realized tha
t\, by coupling the two boundary theories with a relevant perturbation\, A
NEC can be violated\, and the wormhole can be made traversable in a two-si
ded BTZ black hole. We generalize the GJW results to higher-dimensional tr
aversable wormholes in the context of Rindler-AdS/CFT and show that the sa
me result can be obtained using the eikonal approximation. We also introdu
ce the double trace operator with U(1) conserved current operators in the
AdS-Schwarzschild black hole and study the effects of conservation laws on
traversable wormholes. We discuss how the wormhole opening depends on the
charge diffusion constant and how this affects the amount of information
that can be sent through the wormhole.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/74/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christopher Couzens (Kyung-Hee University)
DTSTART;VALUE=DATE-TIME:20220411T070000Z
DTEND;VALUE=DATE-TIME:20220411T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/75
DESCRIPTION:Title: Multi charge Discs and Spindles\nby Christopher Couzens
(Kyung-Hee University) as part of KIAS String Seminars\n\n\nAbstract\nIn t
his talk I will discuss recent advances of the last year in understanding
black holes with disc or spindle horizons. The metrics on these discs and
spindles have non-constant curvature with orbifold singularities\, (or wor
se than orbifold singularities) and they evade the uniformization theorems
. \nDespite the singularities one obtains well-defined string/M-theory sol
utions and in certain cases all singularities in the uplifted theory are r
esolved. We will conclude with some comments on dual field theories.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/75/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seung-Joo Lee (IBS-CTPU)
DTSTART;VALUE=DATE-TIME:20220530T070000Z
DTEND;VALUE=DATE-TIME:20220530T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/76
DESCRIPTION:Title: The fate of not being minimal\nby Seung-Joo Lee (IBS-CTP
U) as part of KIAS String Seminars\n\n\nAbstract\nIn the context of eight-
dimensional F-theory\, we will discuss the physical interpretation of sing
ular fibers with vanishing orders (4\,6\,12) or beyond\, which are known a
s non-minimal fibers. While minimal fibers in codimension-one loci of the
base lead to vector fields valued in a Lie algebra\, non-minimal fibers do
not acquire such a clean interpretation and hence have typically been dis
carded in the literature. In this talk we will clarify the fate of non-min
imal fibers in the language of the effective physics and will put it also
into a more general context of the relevant swampland conjectures for quan
tum gravity.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/76/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuya Tanizaki (Kyoto YITP)
DTSTART;VALUE=DATE-TIME:20220404T070000Z
DTEND;VALUE=DATE-TIME:20220404T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/77
DESCRIPTION:Title: Semiclassical description of confinement via center vortices
and anomaly-preserving T^2 compactifications\nby Yuya Tanizaki (Kyoto
YITP) as part of KIAS String Seminars\n\n\nAbstract\nConfinement of 4d ga
uge theories is usually the strong-coupling problem\, and it is a difficul
t task to understand even its qualitative features. We are trying to devel
op its semiclassical understanding based on the idea of volume independenc
e or adiabatic continuity. We conjecture that the strong-coupling regime o
f many 4d gauge theories is continuously connected to the weak-coupling th
eories on small R2xT2 with the nontrivial ‘t Hooft flux. We explicitly c
onfirm the fractional theta periodicity for pure YM and chiral Lagrangian
for QCD can be derived in this small T2 regime\, which partly justifies ou
r conjecture. We also uncover why this is possible in view of anomaly-pres
ervation of this compactification.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/77/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michele Del Zotto (Uppsala University)
DTSTART;VALUE=DATE-TIME:20220509T080000Z
DTEND;VALUE=DATE-TIME:20220509T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/78
DESCRIPTION:Title: Back to Heterotic Instantons on ALE spaces: F-theory\, 2-gro
ups\, and T-duality\nby Michele Del Zotto (Uppsala University) as part
of KIAS String Seminars\n\n\nAbstract\nThe matching of the 2-group struct
ure constants for T-dual pairs of little string theories is a stringent co
nstraint. In this talk\, I will discuss an application to the problem of c
harting the T-dualities of Heterotic ALE instantons.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/78/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Junho Hong (KU Leuven)
DTSTART;VALUE=DATE-TIME:20220620T070000Z
DTEND;VALUE=DATE-TIME:20220620T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/79
DESCRIPTION:Title: Large N Topologically Twisted Indices\, Holography\, and Bla
ck Holes\nby Junho Hong (KU Leuven) as part of KIAS String Seminars\n\
n\nAbstract\nIn this talk\, I will present a simple closed form expression
for the topologically twisted index of the ABJM theory as a function of t
he magnetic fluxes and complexified electric chemical potentials valid at
fixed k and to all orders in the large N expansion. This in turn leads to
analytic expressions for the topologically twisted index at fixed genus in
the 't Hooft limit\, to all orders in the large λ=N/k expansion. These r
esults have important implications for holography and the microscopic entr
opy counting of supersymmetric static AdS4 black holes. I will also briefl
y discuss generalizations to other SCFTs arising from M2-branes.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/79/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ying-Hsuan Lin (Harvard)
DTSTART;VALUE=DATE-TIME:20220613T070000Z
DTEND;VALUE=DATE-TIME:20220613T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/80
DESCRIPTION:Title: Topological modular forms and Monstrous Moonshine\nby Yi
ng-Hsuan Lin (Harvard) as part of KIAS String Seminars\n\n\nAbstract\nWe u
se the theory of topological modular forms to constrain bosonic holomorphi
c CFTs\, which can be viewed as (0\,1) SCFTs with a trivial right-moving s
upersymmetric sector. A conjecture by Segal\, Stolz and Teichner requires
the constant term of the partition function 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. Applying the constraint to orbifolds of multiple copies of the Mo
nster CFT\, and aided by Borcherds' generalized denominator formula\, we a
re further led to number-theoretic observations on the Fourier coefficient
s of the McKay-Thompson series.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/80/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Manki Kim (MIT)
DTSTART;VALUE=DATE-TIME:20220517T010000Z
DTEND;VALUE=DATE-TIME:20220517T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/81
DESCRIPTION:Title: D-instanton superpotential in string theory\nby Manki Ki
m (MIT) as part of KIAS String Seminars\n\n\nAbstract\nD-instantons genera
te non-perturbative corrections to string theory amplitudes. These correct
ions are of particular importance because they encode non-perturbative eff
ects in string theory and play a prominent role in moduli stabilization. I
n this talk\, I will focus on D-instanton contributions\, more precisely D
(-1) and ED3 instanton contributions\, to the superpotential of low energy
effective theory of string compactification. Computing such contributions
is challenging\, because of the IR divergence due to zero modes of the D-
instanton and the fact that some instanton contributions are expected to b
e generated in the presence of non-trivial RR and NSNS fluxes. To compute
the D-instanton superpotential\, one must compute the one-loop determinant
around the saddle point. Due to the fact that these saddle point solution
s have zero modes\, the overall normalization of the superpotential contri
bution is ambiguous within the worldsheet formalism. I will discuss how on
e can use string field theory to regularize the amplitude to obtain an una
mbiguous answer. In part two of the talk\, I will explain that the D(-1)-i
nstanton contribution is expected to be generated in a non-trivial flux ba
ckground\, hence the direct computation of such effects is currently out o
f reach. I will show how one can use F-theory to compute the D(-1)-instant
on superpotential and argue that in the global Sen-limit the D(-1)-instant
on superpotential is absent.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/81/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ki-Hong Lee (KAIST)
DTSTART;VALUE=DATE-TIME:20220425T070000Z
DTEND;VALUE=DATE-TIME:20220425T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/82
DESCRIPTION:Title: Higgs\, Coulomb and Hall-Littlewood\nby Ki-Hong Lee (KAI
ST) as part of KIAS String Seminars\n\n\nAbstract\nWe study the Higgs bran
ch of class-S theories with twist lines\, by studying their 3d reduction a
nd corresponding mirror dual theories (or magnetic quivers).\nWe find many
of them having the entire 'Higgs branch' fibered over an unbroken Coulomb
branch direction. By this\, we point out the difference between the Higgs
sector and the Hall-Littlewood sector\, which have been long believed to
be identical for genus 0 theories.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/82/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zhenbin Yang (Stanford)
DTSTART;VALUE=DATE-TIME:20220531T020000Z
DTEND;VALUE=DATE-TIME:20220531T030000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/83
DESCRIPTION:Title: Firewalls from Wormholes\nby Zhenbin Yang (Stanford) as
part of KIAS String Seminars\n\n\nAbstract\nI will address an ongoing proj
ect with Douglas Stanford addressing the typical state firewall paradox\,
which is one of the remaining paradox regarding the interior of black hole
s.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/83/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thorsten Schimannek (Sorbonne Université)
DTSTART;VALUE=DATE-TIME:20220810T070000Z
DTEND;VALUE=DATE-TIME:20220810T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/84
DESCRIPTION:Title: Counting BPS states with discrete charges in M-theory\nb
y Thorsten Schimannek (Sorbonne Université) as part of KIAS String Semina
rs\n\n\nAbstract\nDiscrete gauge symmetries can arise in M-theory on Calab
i-Yau threefolds with terminal singularities. I will argue that the Gopaku
mar-Vafa invariants are encoded in partition functions associated to diffe
rent values of a discrete flat but topologically non-trivial B-field that
stabilizes the singularities. Locally\, the effect of the B-field can be i
nterpreted as replacing each node by a non-commutative conifold. This pict
ure allows us to derive closed expressions for the constant map contributi
ons to the topological string partition functions on non-commutative crepa
nt resolutions.\nThe main example in this talk will be singular torus fibe
red Calabi-Yau 3-folds that share the same Jacobian fibrations as smooth g
enus one fibered Calabi-Yaus. Somewhat miraculously\, all of the relevant
partition functions can then be recovered at newly discovered non-commutat
ive large volume limits in the stringy Kähler moduli spaces of a rich net
work of interconnected torus fibrations. This makes it possible to extract
the Gopakumar-Vafa invariants associated to discrete charged BPS states i
n M-theory on singular Calabi-Yau threefolds.\nIf time permits\, I will al
so comment on the F-theory interpretation in terms of twisted elliptic gen
era and use this to deduce the 6d discrete 't Hooft anomaly.\nThe talk is
mainly based on 2108.09311 by the speaker and on work in progress with Alb
recht Klemm\, Sheldon Katz and Eric Sharpe.\nThe application to anomalies
is work in progress with Markus Dierigl and Paul Oehlmann.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/84/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Changha Choi (Perimeter Institute)
DTSTART;VALUE=DATE-TIME:20220704T070000Z
DTEND;VALUE=DATE-TIME:20220704T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/85
DESCRIPTION:Title: Supersymmetry and trace formulas\nby Changha Choi (Perim
eter Institute) as part of KIAS String Seminars\n\n\nAbstract\nIn the cont
ext of supersymmetric quantum mechanics\, we present a new class of supers
ymmetric localization principles with an application to trace formulas in
mathematics describing thermal partition function. Contrary to the standar
d supersymmetric localization\, this new principle deals with a supertrace
of non-supersymmetric observables. Moreover\, the invariant deformation o
n the path integral side localizes onto non-trivial periodic orbits. We il
lustrate the principle by deriving bosonic trace formulas on compact Lie g
roups.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/85/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sungwoo Hong (University of Chicago\, Argonne National Lab)
DTSTART;VALUE=DATE-TIME:20220630T030000Z
DTEND;VALUE=DATE-TIME:20220630T040000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/86
DESCRIPTION:Title: New Anomalies\, TQFTs\, and Confinement in Bosonic Chiral Ga
uge Theories\nby Sungwoo Hong (University of Chicago\, Argonne Nationa
l Lab) as part of KIAS String Seminars\n\n\nAbstract\nIn this talk\, I wil
l introduce a class of four dimensional chiral gauge theories which is pur
ely bosonic. By "bosonic" I mean that these theories do not admit any ferm
ionic gauge invariant operators. Then I discuss possibly the most comprehe
nsive set of `t Hooft anomalies that the theory possesses. For this\, I wi
ll discuss general background \nfields that can be consistently activated.
The final outcome of this is a combination of centers of color\, non-abel
ian flavor symmetry\, and U(1) symmetry of the theory\, which we call CFU
backgrounds. Next\, I will discuss anomaly matching assuming confinement a
s the IR phase. I will show that a combination of the following facts impo
ses serious \nchallenges for the anomaly matching (hence confinement as a
possible IR phase):\n(1) Theory is bosonic\, so no possible composite ferm
ions to match continuous anomalies.\n(2) Theorems regarding existence/abse
nce of "symmetry preserving TQFTs"\n(3) Possible vacuum operators and asso
ciated breaking of flavor symmetries.\n(4) Dimensional analysis and RG flo
w.\n\nFocusing on an example of SU(8) theory with one fermion in rank-2 sy
mmetric and three fermions in the rank-2 antisymmetric representations\, I
will argue that vacuum operators consistent with abelian anomalies must h
ave very large scaling dimensions and consideration of continuous flavor s
ymmetry anomaly ever increase this. This suggests that no single vacuum op
erator survives along the RG-trajectory and the theory is more likely to f
low to IR conformal field theory. Considering another example\, SU(8) theo
ry with two fermions in rank-2 symmetric and six fermions in the rank-2 an
tisymmetric representations\, I will again argue that the theory is highly
unlikely to confine and the most feasible possibility is to flow to the I
R CFT. Interestingly\, these rather remarkable results based on non-pertur
bative analysis are consistent with what the perturbative analysis about t
he IR fixed point suggests.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/86/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edwan Preau (CNRS)
DTSTART;VALUE=DATE-TIME:20220817T070000Z
DTEND;VALUE=DATE-TIME:20220817T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/87
DESCRIPTION:Title: Chern-Simons term and baryons in holographic QCD\nby Edw
an Preau (CNRS) as part of KIAS String Seminars\n\n\nAbstract\nThe hologra
phic method is one of the only ways of getting analytic insight into most
strongly coupled systems. When numerical methods are not available\, it is
even the best technique we know of to tackle these problems. In particula
r\, lattice QCD is unable to provide results at finite baryon density\, wh
ich is why a lot of effort is put into the study of holographic QCD at hig
h density. Densities beyond the nuclear density are not only a theoretical
frontier\, but are reached in real systems such as neutron star cores and
future heavy ion collision experiments. In this talk\, I will discuss the
most elementary aspect of baryonic physics in holography\, that is the st
udy of a single baryon state. I will start by reviewing the top-down const
ruction of Sakai and Sugimoto\, which makes very clear the crucial role pl
ayed by the topological CS term to construct holographic baryons. I will t
hen introduce the bottom-up framework that we use\, the so-called V-QCD fr
amework\, and explain how the CS term is built in V-QCD. The last part of
my presentation will discuss the construction of a baryon solution in V-QC
D\, with the newly determined CS term.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/87/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fengjun Xu (BIMSA\, Beijing)
DTSTART;VALUE=DATE-TIME:20220801T070000Z
DTEND;VALUE=DATE-TIME:20220801T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/88
DESCRIPTION:Title: Topological Defect Lines in Two Dimensional Fermionic CFTs\nby Fengjun Xu (BIMSA\, Beijing) as part of KIAS String Seminars\n\n\nA
bstract\nIn this talk\, we will talk about topological defect lines (TDLs)
in two dimensional (conformal) theories and their roles in category symme
tries\, which generalize the notion of symmetries by including non-inverti
ble elements. In particular\, we will introduce their new features in 2d F
ermionic conformal theories\, as well as their strong constraints in the s
tudy of RG flows. Followed by that\, we will utilise these strong constrai
nts to study a RG flow with emergent supersymmetry in two dimensions.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/88/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fabrizio Del Monte (Université de Montreal)
DTSTART;VALUE=DATE-TIME:20220712T020000Z
DTEND;VALUE=DATE-TIME:20220712T030000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/89
DESCRIPTION:Title: Supersymmetric partition functions and isomonodromic tau fun
ctions\nby Fabrizio Del Monte (Université de Montreal) as part of KIA
S String Seminars\n\n\nAbstract\nClass S theories are four-dimensional N=2
QFTs that are obtained by wrapping M5-branes on Riemann surfaces with sin
gular points. In recent years a correspondence between class S theories an
d isomonodromic deformations equations (whose simplest examples are the si
x Painlevé equations) is emerging\, where the so-called isomonodromic tau
function is identified with the dual partition function of the QFT. The t
au functions can be typically written as Fredholm determinants or Pfaffian
s\, providing a fully nonperturbative approach to study partition function
s of class S theories\, relying only on the geometric data entering in the
string theory construction\, and not on a classical action.\n\nAfter revi
ewing the Fredholm determinant formulation of tau functions for spheres wi
th regular singularities\, corresponding to linear quiver gauge theories\,
I will show how the description can be extended to tau functions with ort
hogonal gauge groups\, that are written as Fredholm Pfaffians\, and to tau
functions for tori with regular singularities\, corresponding to circular
quiver gauge theories. I will conclude by showing how the tau function de
scription allows to study the S-duality transformation of the resulting ga
uge theory dual partition function.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/89/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Haowu Wang (IBS-CGP\, Pohang)
DTSTART;VALUE=DATE-TIME:20220822T070000Z
DTEND;VALUE=DATE-TIME:20220822T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/90
DESCRIPTION:Title: Finite groups and automorphic products\nby Haowu Wang (I
BS-CGP\, Pohang) as part of KIAS String Seminars\n\n\nAbstract\nIn 1992 Bo
rcherds proved Monstrous Moonshine Conjecture by lifting Mckay--Thomson se
ries to twisted denominator identities of the monster Lie algebra. Borcher
ds' proof inspires an intriguing relation between vertex algebras\, Borche
rds--Kac--Moody algebras and automorphic products. In this talk we introdu
ce several new results related to this relation. We classify nice BKM alge
bras whose denominators are automorphic products. We prove twists of denom
inator identities of the fake monster Lie algebra by the Conway group defi
ne automorphic products on orthogonal groups. To prove the results\, we es
tablish a new expression of automorphic products in terms of Jacobi forms.
Using this representation\, we also show that some infinite products invo
lving twisted elliptic genera of K3 surfaces (appearing in Mathieu Moonshi
ne) are meromorphic Siegel modular forms on congruence subgroups\, which p
roves a conjecture of Miranda Cheng. This talk is based on joint work with
Brandon Williams.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/90/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yi Zhang (Peking University)
DTSTART;VALUE=DATE-TIME:20220824T070000Z
DTEND;VALUE=DATE-TIME:20220824T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/91
DESCRIPTION:Title: Gravitational anomalies of higher-spin fields\nby Yi Zha
ng (Peking University) as part of KIAS String Seminars\n\n\nAbstract\nIn t
his talk\, I will consider local gravitational anomalies of symmetric tens
or-spinors (fermionic higher spin fields). This is done by using the Atiya
h-Singer index theorem and the spectrum of ghosts. We find new anomaly can
cellations within an infinite tower of these fermionic higher spin fields
with alternating chiralities. Time permitting\, I will also talk about the
antisymmetric case (fermionic p-forms). The ghost spectrum is found using
the Batalin-Vilkovisky field-antifield formalism. We find an intriguing m
atching of anomalies between a chiral fermionic p-form and a (D-p-1)-form.
\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/91/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Heeyeon Kim (Rutgers)
DTSTART;VALUE=DATE-TIME:20220823T070000Z
DTEND;VALUE=DATE-TIME:20220823T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/93
DESCRIPTION:Title: Four-manifold invariants and Seiberg-Witten theory (1/4)
\nby Heeyeon Kim (Rutgers) as part of KIAS String Seminars\n\n\nAbstract\n
I will review the work of Moore and Witten in 1997\, which provided a path
integral derivation of the Donaldson invariants via topologically twisted
4d supersymmetric gauge theories on a closed four-manifold. If time permi
ts\, I will also report recent progress in understanding analogous computa
tions in higher dimensions.\n*organizer's comment\; this is the first lect
ure of three-times-long lecture series.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/93/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Heeyeon Kim (Rutgers)
DTSTART;VALUE=DATE-TIME:20220825T070000Z
DTEND;VALUE=DATE-TIME:20220825T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/94
DESCRIPTION:Title: Four-manifold invariants and Seiberg-Witten theory (2/4)
\nby Heeyeon Kim (Rutgers) as part of KIAS String Seminars\n\n\nAbstract\n
I will review the work of Moore and Witten in 1997\, which provided a path
integral derivation of the Donaldson invariants via topologically twisted
4d supersymmetric gauge theories on a closed four-manifold. If time permi
ts\, I will also report recent progress in understanding analogous computa
tions in higher dimensions.\n*organizer's comment\; this is the second lec
ture of three-times-long lecture series.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/94/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Usman Naseer (Uppsala University)
DTSTART;VALUE=DATE-TIME:20220905T070000Z
DTEND;VALUE=DATE-TIME:20220905T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/95
DESCRIPTION:Title: 7d SYM\, negative coupling and instantons\nby Usman Nase
er (Uppsala University) as part of KIAS String Seminars\n\n\nAbstract\nBei
ng non-renormalizable\, SYM theories in d>4 are not well-defined by themse
lves and need non-trivial UV-completions. Using supersymmetric localizatio
n\, one can obtain a glimpse into the structure of these UV completions. F
ocusing on the 7d SYM\, we show that there is a regime where the effective
coupling becomes negative. The theory has instanton branes which contribu
te to the partition function non-trivially. Remarkably\, the full partitio
n functions stays well defined even for negative coupling. Our results imp
ly that the UV completion has two weakly coupled regimes\, one of which is
\, in fact\, gravitational.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/95/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Heeyeon Kim (Rutgers)
DTSTART;VALUE=DATE-TIME:20220826T070000Z
DTEND;VALUE=DATE-TIME:20220826T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/96
DESCRIPTION:Title: Four-manifold invariants and Seiberg-Witten theory (3/4)
\nby Heeyeon Kim (Rutgers) as part of KIAS String Seminars\n\n\nAbstract\n
I will review the work of Moore and Witten in 1997\, which provided a path
integral derivation of the Donaldson invariants via topologically twisted
4d supersymmetric gauge theories on a closed four-manifold. If time permi
ts\, I will also report recent progress in understanding analogous computa
tions in higher dimensions.\n*organizer's comment\; this is the third lect
ure of three-times-long lecture series.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/96/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hongfei Shu (BIMSA\, Beijing)
DTSTART;VALUE=DATE-TIME:20220919T070000Z
DTEND;VALUE=DATE-TIME:20220919T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/97
DESCRIPTION:Title: Wall-crossing of TBA equations and WKB periods for the highe
r order ODE\nby Hongfei Shu (BIMSA\, Beijing) as part of KIAS String S
eminars\n\n\nAbstract\nIn this talk\, we study the WKB periods for the thi
rd order ordinary differential equation (ODE) with polynomial potential\,
which is obtained by the Nekrasov-Shatashvili limit of ($A_2\,A_N$) Argyre
s-Douglas theory in the Omega background. In the minimal chamber of the mo
duli space\, we derive the Y-system and the thermodynamic Bethe ansatz (T
BA) equations of quantum integrable model by using the ODE/IM corresponden
ce. The exact WKB periods are identified with the Y-functions. Varying the
moduli parameters of the potential\, the wall-crossing of the TBA equati
ons occurs. We study the process of the wall-crossing from the minimal ch
amber to the maximal chamber for $(A_2\,A_2)$ and $(A_2\,A_3)$ case. When
the potential is a monomial type\, we show the TBA equations obtained from
the ($A_2\, A_2$) and ($A_2\, A_3$)-type ODE lead to the $D_4$ and $E_6$-
type TBA equations respectively. This talk is based on the joint work with
Katsushi Ito and Takayasu Kondo arXiv:2111.11047 [hep-th].\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/97/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Heeyeon Kim (Rutgers)
DTSTART;VALUE=DATE-TIME:20220830T070000Z
DTEND;VALUE=DATE-TIME:20220830T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/98
DESCRIPTION:Title: Four-manifold invariants and Seiberg-Witten theory (4/4)
\nby Heeyeon Kim (Rutgers) as part of KIAS String Seminars\n\n\nAbstract\n
I will review the work of Moore and Witten in 1997\, which provided a path
integral derivation of the Donaldson invariants via topologically twisted
4d supersymmetric gauge theories on a closed four-manifold. If time permi
ts\, I will also report recent progress in understanding analogous computa
tions in higher dimensions.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/98/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuta Hamada (KEK)
DTSTART;VALUE=DATE-TIME:20221024T070000Z
DTEND;VALUE=DATE-TIME:20221024T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/100
DESCRIPTION:Title: Monopole-fermion scattering and varying Fock space\nby
Yuta Hamada (KEK) as part of KIAS String Seminars\n\n\nAbstract\nWe propos
e a four-dimensional interpretation of the outgoing state of the scatterin
g of a massless fermion off a Dirac monopole. It has been known that such
a state has fractional fermion numbers and is necessarily outside the Fock
space on top of ordinary perturbative vacuum\, when more than two flavour
s of charged Dirac fermions are considered. In this paper\, we point out t
hat the Fock space of the fermions depends on the rotor degree of freedom
of the monopole and changes by a monopole-fermion s-wave scattering. By up
lifting the fermion-rotor system introduced by Polchinski\, from two to fo
ur dimensions\, we argue that the outgoing state can be understood as a st
ate in a different Fock space.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/100/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiung Hwang (IBS\, Daejon)
DTSTART;VALUE=DATE-TIME:20221031T070000Z
DTEND;VALUE=DATE-TIME:20221031T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/101
DESCRIPTION:Title: Rethinking 3d Mirror Symmetry\nby Chiung Hwang (IBS\, D
aejon) as part of KIAS String Seminars\n\n\nAbstract\nI'll discuss how to
understand the local S-dualization and the Hanany-Witten transition of bra
nes in IIB string theory in terms of QFT dualities. This new approach lead
s to a systematic construction of the mirror dual of any 3d N=4 linear qui
ver gauge theory only using a set of basic dualities. Also\, I'll discuss
a relation between 3d mirror symmetry and Seiberg-like dualities.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/101/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simone Giacomelli (Milan University)
DTSTART;VALUE=DATE-TIME:20221107T070000Z
DTEND;VALUE=DATE-TIME:20221107T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/102
DESCRIPTION:Title: A journey through Argyres-Douglas theories\nby Simone G
iacomelli (Milan University) as part of KIAS String Seminars\n\n\nAbstract
\nArgyres-Douglas theories are a vast class of N=2 superconformal theories
in four dimensions characterized by the presence of chiral primary operat
ors with fractional scaling dimension. Although these models are strongly-
coupled\, in this talk I will explain how their geometric realization in s
tring theory allows us to extract extremely detailed information about the
ir dynamics and their moduli space of vacua. In particular I will discuss
new results I have obtained about the description of their Higgs branch an
d the determination of their generalized symmetries.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/102/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aaron Poole (Kyung Hee University)
DTSTART;VALUE=DATE-TIME:20221121T070000Z
DTEND;VALUE=DATE-TIME:20221121T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/104
DESCRIPTION:Title: Charges\, conserved quantities\, and fluxes in de Sitter sp
acetime\nby Aaron Poole (Kyung Hee University) as part of KIAS String
Seminars\n\n\nAbstract\nIn this talk I will discuss conserved quantities i
n asymptotically locally de Sitter (dS) spacetimes\, motivated by the broa
der aim of a developing a fully nonlinear understanding of the nature of g
ravitational waves in dS. I will begin with a review of the asymptotics of
dS spacetimes\, before showing that one can use the tools of the covarian
t phase space formalism (together with analytic continuation of analogous
results in anti-de Sitter spacetime) in order to derive expressions for sp
atially conserved charges and temporally conserved quantities. I will pres
ent flux formulae which capture the effects of outgoing gravitational radi
ation and illustrate these via application to exact solutions\, with parti
cular emphasis on the Robinson-Trautman dS class. This talk is based on ht
tps://arxiv.org/pdf/2112.14210.pdf (published in PRD) and upcoming work in
collaboration with Kostas Skenderis and Marika Taylor.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/104/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sahand Seifnashri (IAS)
DTSTART;VALUE=DATE-TIME:20221018T010000Z
DTEND;VALUE=DATE-TIME:20221018T020000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/105
DESCRIPTION:Title: Representation theory for non-invertible symmetries and asy
mptotic density of states\nby Sahand Seifnashri (IAS) as part of KIAS
String Seminars\n\n\nAbstract\nWe discuss non-invertible symmetries that g
eneralize group-like symmetries in QFTs. We find the appropriate notion of
representation for non-invertible symmetries needed to derive selection r
ules on correlation functions. We use this understanding to derive a Cardy
-like formula for 2d CFTs with a finite non-invertible symmetry. More spec
ifically\, we derive a universal formula for the asymptotic density of sta
tes transforming in an irreducible representation of a non-invertible symm
etry.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/105/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yasuyuki Hatsuda (Rikkyo University)
DTSTART;VALUE=DATE-TIME:20221205T070000Z
DTEND;VALUE=DATE-TIME:20221205T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/106
DESCRIPTION:Title: Fermi-gas approach to supersymmetric localization\nby Y
asuyuki Hatsuda (Rikkyo University) as part of KIAS String Seminars\n\n\nA
bstract\nSupersymmetric localization reduces path integrals to finite dime
nsional matrix integrals. For some particular models\, these matrix integr
als can be regarded as the canonical partition function of ideal Fermi-gas
systems. I will first review this Fermi-gas approach in detail. Then\, I
will talk about our recent application to (a special limit of) superconfor
mal indices.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/106/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Brandon C. Rayhaun (Stony Brook University)
DTSTART;VALUE=DATE-TIME:20221213T070000Z
DTEND;VALUE=DATE-TIME:20221213T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/107
DESCRIPTION:Title: Classification of Unitary Rational Conformal Field Theories
with Small Central Charge and Few Primaries\nby Brandon C. Rayhaun (S
tony Brook University) as part of KIAS String Seminars\n\n\nAbstract\nTwo-
dimensional conformal field theories are ubiquitous in physics and mathema
tics. In many applications\, it can be useful to have some kind of handle
on the space of physically consistent theories. It is natural to stratify
this space in terms of two parameters: the central charge c\, and the numb
er of primary operators p. In a classic paper\, Schellekens classified all
theories with p=1 primaries and central charge c less than or equal to 24
. In this talk\, I will describe a strategy for pushing the classification
to larger values of p. As a proof of concept\, I will spell out the case
of p=2\, emphasizing the new concepts at play and highlighting several fut
ure directions. Based on joint work with Sunil Mukhi.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/107/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Julio\, Parra Martinez (Caltech)
DTSTART;VALUE=DATE-TIME:20221219T070000Z
DTEND;VALUE=DATE-TIME:20221219T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/108
DESCRIPTION:Title: Causality constraints on gravitational effective theories\nby Julio\, Parra Martinez (Caltech) as part of KIAS String Seminars\n\
n\nAbstract\nIn this talk I will describe constraints from causality and u
nitarity on 2→2 graviton scattering in weakly-coupled gravitational effe
ctive field theories. Together\, causality and unitarity imply dispersion
relations that connect low-energy observables to high-energy data. Using s
uch dispersion relations\, I will explain how to derive two-sided bounds o
n gravitational Wilson coefficients in terms of the mass M of new higher-s
pin states. Such bounds imply that gravitational interactions must shut of
f uniformly in the limit G→0\, and prove the scaling with M expected fro
m dimensional analysis. In addition they demonstrate the gravity must be w
eakly coupled at all scales below Planck.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/108/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Deliang Zhong (Tel Aviv University)
DTSTART;VALUE=DATE-TIME:20230206T070000Z
DTEND;VALUE=DATE-TIME:20230206T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/109
DESCRIPTION:Title: Line Operators in Chern-Simons-Matter Theories and Bosoniza
tion in Three Dimensions\nby Deliang Zhong (Tel Aviv University) as pa
rt of KIAS String Seminars\n\n\nAbstract\nWe study Chern-Simons theories a
t large N with either bosonic or fermionic matter in the fundamental repre
sentation. The most fundamental operators in these theories are mesonic li
ne operators\, the simplest example being Wilson lines ending on fundament
als. We classify the conformal line operators along an arbitrary smooth pa
th as well as the spectrum of conformal dimensions and transverse spins of
their boundary operators at finite 't Hooft coupling. These line operator
s are shown to satisfy first-order chiral evolution equations\, in which a
smooth variation of the path is given by a factorized product of two line
operators. We argue that this equation\, together with the spectrum of bo
undary operators\, are sufficient to determine these operators' expectatio
n values uniquely. We demonstrate this by bootstrapping the two-point func
tion of the displacement operator on a straight line. We show that the lin
e operators in the theory of bosons and the theory of fermions satisfy the
same evolution equation and have the same spectrum of boundary operators.
\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/109/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zhenghao Zhong (Oxford)
DTSTART;VALUE=DATE-TIME:20230213T070000Z
DTEND;VALUE=DATE-TIME:20230213T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/110
DESCRIPTION:Title: Higgsing SCFTs in d=3\,4\,5\,6\nby Zhenghao Zhong (Oxfo
rd) as part of KIAS String Seminars\n\n\nAbstract\nWe study supersymmetric
gauge theories with 8 supercharges in d=3\,4\,5\,6. For these theories\,
one can perform Higgsings by turning on VEVs of scalar fields. However\, t
his process can often be difficult when dealing with superconformal field
theories (SCFTs) where the Lagrangian is often not known. Using techniques
of magnetic quivers and a new algorithm we call "Inverted Quiver Subtract
ion"\, we show how one can easily obtain the SCFT(s) after Higgsing. This
technique can be equally well applied to SCFTs in d=3\,4\,5\,6.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/110/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rishi Mouland (Cambridge)
DTSTART;VALUE=DATE-TIME:20230220T080000Z
DTEND;VALUE=DATE-TIME:20230220T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/111
DESCRIPTION:Title: Black Holes in the Dual of Quantum Mechanics\nby Rishi
Mouland (Cambridge) as part of KIAS String Seminars\n\n\nAbstract\nI will
motivate and study a holographic duality between on one hand a theory of s
uperconformal quantum mechanics\, and on the other\, M-theory on a particu
lar background. I will exhibit a broad class of black hole solutions\, who
se entropy must be captured by a degeneracy of states in the quantum mecha
nics. Through an asymptotic study of the superconformal index in the super
gravity regime\, I will provide such a microstate counting for those black
holes that are supersymmetric. I will finally discuss on the role of dual
ities of this form in constructing the basic building blocks of holography
for SCFTs in various dimensions.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/111/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emily Nardoni (IPMU)
DTSTART;VALUE=DATE-TIME:20230227T070000Z
DTEND;VALUE=DATE-TIME:20230227T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/112
DESCRIPTION:Title: Probing Anomalies of Non-Invertible Symmetries with Symmetr
y TFTs\nby Emily Nardoni (IPMU) as part of KIAS String Seminars\n\n\nA
bstract\n't Hooft anomalies provide crucial insight into the properties of
quantum field theories\, imposing powerful constraints on their low energ
y dynamics. For invertible global symmetries\, it is known that the 't Hoo
ft anomalies can be characterized by an invertible TQFT in one higher dime
nsion. However\, the analogous statement remains to be understood for non-
invertible symmetries. In this talk we will discuss how the linking invari
ants in a non-invertible TQFT known as the Symmetry TFT can be used as a d
iagnostic for the anomalies of non-invertible symmetries. We will illustra
te this proposal through examples in two and four dimensions\, including 4
d adjoint QCD\, and comment on how knowledge of these anomalies can impose
constraints on the dynamics.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/112/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hossein Yavartanoo (BIMSA)
DTSTART;VALUE=DATE-TIME:20230208T070000Z
DTEND;VALUE=DATE-TIME:20230208T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/113
DESCRIPTION:Title: Null Surface Thermodynamics\nby Hossein Yavartanoo (BIM
SA) as part of KIAS String Seminars\n\n\nAbstract\nFormulating D dimension
al pure Einstein gravity in spacetimes with a null codimension one boundar
y requires addition of boundary degrees of freedom (BDOF) to the usual bul
k gravitons. We construct the solution space perturbatively around the nul
l boundary in which BDOF is described by D functions on the codimension on
e null boundary. Employing covariant phase space formalism we compute char
ges associated with symmetries which rotate us within the solution phase s
pace. We establish that the system admits a thermodynamic description and
that the null surface thermodynamics is a consequence of the diffeomorphis
m invariance of the theory\, not relying on other special features of the
null surface or the gravity theory. In the presence of flux of bulk gravit
ons through the null boundary we deal with an open thermodynamic system. O
ur analysis here extends the usual laws of black hole thermodynamics in tw
o ways: it is true for any null surface (which is not necessarily the hori
zon of a black hole) which may describe a system out of thermal equilibriu
m and that they are local equations over the null surface.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/113/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lorenz Eberhardt (IAS)
DTSTART;VALUE=DATE-TIME:20230307T013000Z
DTEND;VALUE=DATE-TIME:20230307T030000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/114
DESCRIPTION:Title: Evaluating one-loop string amplitudes\nby Lorenz Eberha
rdt (IAS) as part of KIAS String Seminars\n\n\nAbstract\nI will explain re
cent work with S. Mizera in which we give explicit evaluations of one-loop
open string amplitudes at finite alpha’. Our method involves various de
formations of the contour integral over the modular parameter \\tau. We di
rectly verify that the one-loop string amplitude satisfies unitarity const
raints. I will show explicit plots of the amplitude which will allow us to
verify directly physical conjectures about their behavior\, especially at
high energies.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/114/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matteo Lotito (SNU)
DTSTART;VALUE=DATE-TIME:20230313T070000Z
DTEND;VALUE=DATE-TIME:20230313T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/115
DESCRIPTION:Title: Extended operators in 4d N=2 SCFTs and vertex algebras\
nby Matteo Lotito (SNU) as part of KIAS String Seminars\n\n\nAbstract\nLoc
al Schur operators in 4d N=2 SCFTs form a protected class of operators giv
ing rise to a 2d vertex operator algebra. Following the local operator pic
ture\, we introduce classes of conformal extended operators (lines\, surfa
ces) and study these in twisted Schur cohomology. We show how these operat
ors support a more general algebraic structure compared to the local case\
, giving rise to an extension of the vertex algebra known for local Schur
operators.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/115/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Minyoung You (Postech)
DTSTART;VALUE=DATE-TIME:20230320T070000Z
DTEND;VALUE=DATE-TIME:20230320T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/116
DESCRIPTION:Title: MTC/RCFT correspondence: the fermionic story\nby Minyou
ng You (Postech) as part of KIAS String Seminars\n\n\nAbstract\nIt is well
-known that modular tensor categories (MTC)\, which describe 2+1d bosonic
topological orders\, define a 2+1d topological quantum field theory (TQFT)
and capture the modular data of 1+1d rational conformal field theories (R
CFT). After reviewing the bosonic correspondence\, I will explain the gene
ralization of this correspondence to the fermionic case: fermionic topolog
ical orders are described by super-MTCs\, their modular extensions define
a 2+1d spin-TQFT\, and they capture the modular data of 1+1d fermionic RCF
Ts. Then I will discuss the classification of super-MTCs and computation o
f their modular extensions. Finally\, I will discuss the application of th
ese classification results to fermionic RCFTs. In particular\, the knowled
ge of modular extensions allows us to glean information about the R-R sect
or from the data of the NS-NS sector.\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/116/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wei Gu (Bonn)
DTSTART;VALUE=DATE-TIME:20230327T070000Z
DTEND;VALUE=DATE-TIME:20230327T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/117
DESCRIPTION:Title: Heisenberg Spin Chains And Supersymmetric Gauge Theories\nby Wei Gu (Bonn) as part of KIAS String Seminars\n\n\nAbstract\nIn this
talk\, we will present how a Heisenberg spin chain emerges from the two-d
imensional N=(2\,2) gauge theory at an intermediate scale\, which relies o
n the renormalization group flow guided by the global symmetries and the d
ynamics of domain walls. Two examples will be discussed: XX-model and its
K-theoretic version. Finally\, we will briefly comment on the unification
of gauge theories from the point of view of the spin chain\, and how to ap
proach other formulations of an integrable system via a new point of view.
\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/117/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cyril Closset (Birmingham)
DTSTART;VALUE=DATE-TIME:20230403T070000Z
DTEND;VALUE=DATE-TIME:20230403T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/118
DESCRIPTION:by Cyril Closset (Birmingham) as part of KIAS String Seminars\
n\nInteractive livestream: https://zoom.us/j/93792862365\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/118/
URL:https://zoom.us/j/93792862365
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michèle Levi (Oxford)
DTSTART;VALUE=DATE-TIME:20230406T030000Z
DTEND;VALUE=DATE-TIME:20230406T040000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/119
DESCRIPTION:by Michèle Levi (Oxford) as part of KIAS String Seminars\n\nI
nteractive livestream: https://zoom.us/j/93792862365\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/119/
URL:https://zoom.us/j/93792862365
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michèle Levi (Oxford)
DTSTART;VALUE=DATE-TIME:20230410T070000Z
DTEND;VALUE=DATE-TIME:20230410T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/120
DESCRIPTION:by Michèle Levi (Oxford) as part of KIAS String Seminars\n\nI
nteractive livestream: https://zoom.us/j/93792862365\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/120/
URL:https://zoom.us/j/93792862365
END:VEVENT
BEGIN:VEVENT
SUMMARY:Justin Kaidi (University of Washington)
DTSTART;VALUE=DATE-TIME:20230418T020000Z
DTEND;VALUE=DATE-TIME:20230418T030000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/121
DESCRIPTION:by Justin Kaidi (University of Washington) as part of KIAS Str
ing Seminars\n\nInteractive livestream: https://zoom.us/j/93792862365\nAbs
tract: TBA\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/121/
URL:https://zoom.us/j/93792862365
END:VEVENT
BEGIN:VEVENT
SUMMARY:Amir-Kian Kashani-Poor (ENS Paris)
DTSTART;VALUE=DATE-TIME:20230424T080000Z
DTEND;VALUE=DATE-TIME:20230424T090000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/122
DESCRIPTION:by Amir-Kian Kashani-Poor (ENS Paris) as part of KIAS String S
eminars\n\nInteractive livestream: https://zoom.us/j/93792862365\nAbstract
: TBA\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/122/
URL:https://zoom.us/j/93792862365
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sangmin Lee (Seoul National University)
DTSTART;VALUE=DATE-TIME:20230501T070000Z
DTEND;VALUE=DATE-TIME:20230501T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/123
DESCRIPTION:by Sangmin Lee (Seoul National University) as part of KIAS Str
ing Seminars\n\nInteractive livestream: https://zoom.us/j/93792862365\nAbs
tract: TBA\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/123/
URL:https://zoom.us/j/93792862365
END:VEVENT
BEGIN:VEVENT
SUMMARY:Frank Ferrari (Université libre de Bruxelles)
DTSTART;VALUE=DATE-TIME:20230417T070000Z
DTEND;VALUE=DATE-TIME:20230417T080000Z
DTSTAMP;VALUE=DATE-TIME:20230330T210056Z
UID:kias-string-seminars/124
DESCRIPTION:by Frank Ferrari (Université libre de Bruxelles) as part of K
IAS String Seminars\n\nInteractive livestream: https://zoom.us/j/937928623
65\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/kias-string-seminars/124/
URL:https://zoom.us/j/93792862365
END:VEVENT
END:VCALENDAR