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BEGIN:VEVENT
SUMMARY:Suvrat Raju (ICTS\, Bengaluru)
DTSTART;VALUE=DATE-TIME:20200504T093000Z
DTEND;VALUE=DATE-TIME:20200504T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/1
DESCRIPTION:Title: The holographic nature of null infinity\nby Suvrat Raju
(ICTS\, Bengaluru) as part of ICTS virtual seminar\n\n\nAbstract\nI will
argue that a careful examination of the low energy properties of quantum g
ravity\, together with reasonable assumptions about the UV theory\, leads
to insights into the origin of holography in anti-de Sitter space. The sam
e techniques also lead to a clear conjecture about how quantum information
is localized in asymptotically flat spacetimes. The conjecture is that\,
in quantum gravity\, all information about massless excitations can be obt
ained from an infinitesimal neighbourhood of the past boundary of future
null infinity and does not require observations over all of future null in
finity. In the context of the information paradox\, this suggests that the
fine-grained von Neumann entropy of the state defined on a segment (-\\in
fty\,u) of future null infinity is independent of u. This conjecture also
implies that the oft-discussed "Page curve" may be a misleading target to
aim for in analyses of black hole evaporation.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matteo Baggioli (IFT UAM-CSIC)
DTSTART;VALUE=DATE-TIME:20200506T093000Z
DTEND;VALUE=DATE-TIME:20200506T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/2
DESCRIPTION:Title: From Hydrodynamics to Viscoelasticity in Holography and
beyond ...\nby Matteo Baggioli (IFT UAM-CSIC) as part of ICTS virtual sem
inar\n\n\nAbstract\nHow to construct a holographic model for viscoelastic
materials ?\n\nWhy can that be useful and for what purpose ?\nWhich is the
hydrodynamics behind these models ?\nWhat do these models have in common
with quasicrystals ?\nWhat is a diffusive Goldstone mode and when does it
appear ?\nHow and in which sense are solids different from fluids ?\nWhat
do theory and experiments in confined fluids tell us ?\nHow do glasses and
Weyl semimetals sound ?\n\nThese are the questions that I will discuss w
ith you during my talk!\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gautam Mandal (TIFR\, Mumbai)
DTSTART;VALUE=DATE-TIME:20200513T093000Z
DTEND;VALUE=DATE-TIME:20200513T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/3
DESCRIPTION:Title: Holographic interpretation of Bulk entanglement entropy
\nby Gautam Mandal (TIFR\, Mumbai) as part of ICTS virtual seminar\n\n\nAb
stract\nWe propose a holographic interpretation of entanglement entropy (E
E) of a spatial subregion A in the bulk\, in terms of the reduced density
matrix for an appropriate sub algebra of observables\nin the boundary fiel
d theory/boundary quantum mechanics. The construct in the boundary theory
corresponds to partitioning of the target space and is called a target spa
ce EE. We discuss this in the context of supergravity dual of Dp brane f
ield theories\, in particular for D0 brane quantum mechanics. We find qual
itative agreement between the bulk and boundary calculations.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Maldacena (IAS\, Princeton)
DTSTART;VALUE=DATE-TIME:20200522T113000Z
DTEND;VALUE=DATE-TIME:20200522T123000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/4
DESCRIPTION:Title: Magnetic black holes\nby Juan Maldacena (IAS\, Princeto
n) as part of ICTS virtual seminar\n\n\nAbstract\nWe discuss properties of
magnetically charged black holes in the\nStandard Model. We will discuss
how the electroweak symmetry is restored\naround the black hole. In additi
on\, the Hawking evaporation rate is\ngreatly enhanced by a factor of the
charge of the black hole.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Leopoldo Pando Zayas (University of Michigan)
DTSTART;VALUE=DATE-TIME:20200527T103000Z
DTEND;VALUE=DATE-TIME:20200527T113000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/5
DESCRIPTION:Title: Precision microstate counting of AdS black hole entropy
\nby Leopoldo Pando Zayas (University of Michigan) as part of ICTS virtual
seminar\n\n\nAbstract\nI will describe how within eleven dimensional supe
rgravity one can compute the logarithmic correction to the Bekenstein-Hawk
ing entropy of certain magnetically charged asymptotically AdS$_4$ black h
oles with arbitrary horizon topology. The result perfectly agrees with th
e dual field theory computation of the topologically twisted index in ABJ
M theory and in certain theories obtained from M5 wrapping a hyperbolic 3-
manifold. The extension to rotating\, electrically charged AdS$_4$ black h
oles and the dual superconformal index will also be discussed.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Per Kraus (UCLA)
DTSTART;VALUE=DATE-TIME:20200604T160000Z
DTEND;VALUE=DATE-TIME:20200604T170000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/6
DESCRIPTION:Title: Anomalous Dimensions from Thermal AdS Partition Functio
ns\nby Per Kraus (UCLA) as part of ICTS virtual seminar\n\n\nAbstract\nI w
ill present an efficient method for computing thermal partition functions
of weakly coupled scalar fields in AdS. We consider quartic contact intera
ctions and show how to evaluate the relevant two-loop vacuum diagrams with
out performing any explicit AdS integration\, the key step being the use o
f Kallen-Lehmann type identities. This leads to a simple method for extrac
ting double-trace anomalous dimensions in any spacetime dimension\, recove
ring known first-order results in a streamlined fashion.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Larus Thorlacius (University of Iceland)
DTSTART;VALUE=DATE-TIME:20200608T093000Z
DTEND;VALUE=DATE-TIME:20200608T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/7
DESCRIPTION:Title: Page curves in asymptotically flat spacetime\nby Larus
Thorlacius (University of Iceland) as part of ICTS virtual seminar\n\n\nAb
stract\nIf black hole evaporation is a unitary process\, the entanglement
entropy between the \noutgoing Hawking radiation and the quantum state des
cribing the remaining black hole \nis expected to follow a so-called Page
curve as a function of time. A Page curve for an \nevaporating black hole
in asymptotically flat spacetime can be computed analytically by\nadapting
the Quantum Ryu-Takayanagi (QRT) proposal to a solvable two-dimensional \
ndilaton gravity theory. The associated Page time is found to be one third
of the black \nhole lifetime\, at leading order in semi-classical correct
ions. A Page curve can also be \nobtained for a semi-classical eternal bla
ck hole\, where energy loss due to Hawking \nevaporation is balanced by an
incoming energy flux.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zhenbin Yang (Stanford)
DTSTART;VALUE=DATE-TIME:20200610T033000Z
DTEND;VALUE=DATE-TIME:20200610T043000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/8
DESCRIPTION:Title: Finite-cutoff JT gravity and self-avoiding loops\nby Zh
enbin Yang (Stanford) as part of ICTS virtual seminar\n\n\nAbstract\nWe st
udy quantum JT gravity at finite cutoff using a mapping to the statistical
mechanics of a self-avoiding loop in hyperbolic space\, with positive pre
ssure and fixed length. The semiclassical limit (small $G_{N}$) correspond
s to large pressure\, and we solve the problem in that limit in three over
lapping regimes that apply for different loop sizes. For intermediate loop
sizes\, a semiclassical effective description is valid\, but for very lar
ge or very small loops\, fluctuations dominate. For large loops\, this qua
ntum regime is controlled by the Schwarzian theory. For small loops\, the
effective description fails altogether\, but the problem is controlled usi
ng a conjecture from the theory of self-avoiding walks.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoff Penington (Stanford University)
DTSTART;VALUE=DATE-TIME:20200624T033000Z
DTEND;VALUE=DATE-TIME:20200624T043000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/9
DESCRIPTION:Title: Replica Wormholes\, Entanglement Wedges and the Black H
ole Information Paradox\nby Geoff Penington (Stanford University) as part
of ICTS virtual seminar\n\n\nAbstract\nHawking famously argued\, based on
semiclassical calculations\, that the radiation from evaporating black hol
es is always perfectly thermal and contains no information about the matte
r that fell in. Such a result is inconsistent with the unitarity of quantu
m mechanics. In this talk\, I will argue that a more careful replica trick
calculation shows that the gravitational path integral becomes dominated
at late times by saddles containing spacetime wormholes. These wormholes c
ause the entropy to decrease after the Page time\, consistent with unitari
ty\, and allow information to escape from the interior of the black hole.
In very simple toy models\, we can evaluate the path integral exactly\, an
d see the information emerge. In more realistic black holes\, the full wor
mhole solutions cannot be found explicitly. However\, their existence\, an
d their most important consequences\, can be derived by studying the locat
ion and properties of a non-trivial ‘quantum extremal surface’ in the
original Hawking solution.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nabamita Banerjee (IISER\, Bhopal)
DTSTART;VALUE=DATE-TIME:20200626T093000Z
DTEND;VALUE=DATE-TIME:20200626T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/10
DESCRIPTION:Title: A 3D flat-space holography inspired by AdS3/CFT2 dualit
y\nby Nabamita Banerjee (IISER\, Bhopal) as part of ICTS virtual seminar\n
\n\nAbstract\nI shall mostly talk about the status of flat-space holograph
y in three space time dimensions. The works are in parallel to AdS3/CFT2 d
uality. I shall end with the open ends in the field.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sean Hartnoll (Stanford University)
DTSTART;VALUE=DATE-TIME:20200723T123000Z
DTEND;VALUE=DATE-TIME:20200723T133000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/11
DESCRIPTION:Title: Bootstrapping Matrix Quantum Mechanics\nby Sean Hartnol
l (Stanford University) as part of ICTS virtual seminar\n\n\nAbstract\nMat
rix quantum mechanics theories are at the heart of holography\, but only t
he simple case of a single matrix has been tractable. We have developed a
new method to calculate the spectrum and expectation values of operators i
n matrix quantum mechanics\, including with multiple matrices. Firstly\, w
e relate the expectation values of simple operators to those of more compl
icated operators. We then impose certain positivity constraints on the lon
ger operators. This is seen to strongly constrain the simple expectation v
alues. Using this method\, we easily reproduce the known solution of singl
e-matrix quantum mechanics\, and then go on to obtain new results on the g
round state of two-matrix quantum mechanics. This talk is based on 2004.10
212.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arnab Priya Saha (HRI)
DTSTART;VALUE=DATE-TIME:20200617T093000Z
DTEND;VALUE=DATE-TIME:20200617T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/12
DESCRIPTION:Title: Double soft theorem in generalized bi-adjoint scalars\n
by Arnab Priya Saha (HRI) as part of ICTS virtual seminar\n\n\nAbstract\nI
n CHY formalism\, scattering equations map the kinematic space of Mandelst
am invariants to the points on $\\mathbb{CP}^{1}$. Recently Cachazo\, Ear
ly\, Guevara and Mizera have introduced generalization to the scattering e
quations on higher dimensional projective spaces\, $\\mathbb{CP}^{k-1}$. B
i-adjoint scalar amplitude is a well studied example of this generalisati
on. We study double soft limits of the generalised bi-adjoint scalar ampli
tudes for $k=3$. \n \nThis talk is based on the work in progress with Md.
Abhishek\, Subramanya Hegde and Dileep P. Jatkar\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoffrey Compere (Université libre de Bruxelles)
DTSTART;VALUE=DATE-TIME:20200619T093000Z
DTEND;VALUE=DATE-TIME:20200619T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/13
DESCRIPTION:Title: The BMS group in (A)dS\nby Geoffrey Compere (Universit
é libre de Bruxelles) as part of ICTS virtual seminar\n\n\nAbstract\nRece
nt work has uncovered interesting connections between memory effects\, sof
t theorems and BMS asymptotic symmetries in the infrared structure of asym
ptotically flat gravity. In this talk\, I will present the AdS/dS generali
zation of the BMS symmetries. I will discuss the realization of these “L
ambda-BMS” symmetries as a surface charge algebra. I will also show that
the asymptotically flat BMS surface charge algebra is recovered in the as
ymptotically flat limit only after adding corner terms in the variational
principle in addition to the standard holographic counterterms.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Douglas Stanford (Stanford)
DTSTART;VALUE=DATE-TIME:20200708T033000Z
DTEND;VALUE=DATE-TIME:20200708T043000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/14
DESCRIPTION:Title: On the density matrix of the Hawking radiation\nby Doug
las Stanford (Stanford) as part of ICTS virtual seminar\n\n\nAbstract\nWe
set up the computation of the density matrix of the Hawking radiation by c
omputing inner products of black hole states projected onto different hist
ories of Hawking radiation. A simple computation of these inner products s
uggests that an ensemble average is implicit in the simple gravity descrip
tion.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tom Hartman (Cornell)
DTSTART;VALUE=DATE-TIME:20200715T120000Z
DTEND;VALUE=DATE-TIME:20200715T130000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/15
DESCRIPTION:Title: Holographic duality for averaged free CFTs\nby Tom Hart
man (Cornell) as part of ICTS virtual seminar\n\n\nAbstract\nI will descri
be recent progress on the connections among the conformal bootstrap\, the
sphere packing problem\, and quantum gravity in three dimensions. This lea
ds us toward a holographic duality between Narain CFTs averaged over modul
i and a Chern-Simons-like theory of "U(1) gravity"\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Subhroneel Chakrabarti (The Institute of Mathematical Sciences (IM
Sc)\, Chennai)
DTSTART;VALUE=DATE-TIME:20200821T093000Z
DTEND;VALUE=DATE-TIME:20200821T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/16
DESCRIPTION:Title: Pure Spinor Superstrings: Massive States\nby Subhroneel
Chakrabarti (The Institute of Mathematical Sciences (IMSc)\, Chennai) as
part of ICTS virtual seminar\n\n\nAbstract\nPure Spinor formulation\, intr
oduced by Nathan Berkovits 20 years ago\, is the only known Super-Poincare
covariant worldsheet formulation of superstring theory. The last two deca
des saw pure spinor formulation emerge as the most efficient way to comput
e string amplitudes\, especially at higher loop levels. However\, most of
these successes revolved around external massless states and the massive s
tates remained largely unexplored. In this talk\, I will describe the rece
nt development in understanding the massive states of superstrings in pure
spinor formalism\, as carried out in a series of works by me and my colla
borators. We will present the first proposal for systematic covariant cons
truction of massive vertex operators and discuss how that proposal lead to
the construction of integrated massive vertex for the first time\, as wel
l as its fully covariant theta expansion. With these new results\, we will
also explain how for the first time an explicit equivalence of pure spino
r and the well-known RNS formalism for massive states was achieved. I will
assume no prior knowledge of pure spinor formulation from the audience an
d spend some time introducing this formalism to make the talk more accessi
ble to a comparatively larger audience.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:R Loganayagam (ICTS\, Bengaluru)
DTSTART;VALUE=DATE-TIME:20200422T093000Z
DTEND;VALUE=DATE-TIME:20200422T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/17
DESCRIPTION:Title: Open QFTs from holography\nby R Loganayagam (ICTS\, Ben
galuru) as part of ICTS virtual seminar\n\n\nAbstract\nIn this talk\, I wi
ll outline a formalism to study open quantum field theories using holograp
hic methods. More precisely\, I will consider a quantum field theory (the
system) coupled to a holographic field theory at finite temperature (the e
nvironment). The aim here is to integrate out the holographic environment
with an aim of obtaining an effective dynamics for the resulting open quan
tum field theory. This is done using semiclassical gravitational Schwinger
-Keldysh saddle geometries obtained by complexifying black hole spacetim
es. In addition to shedding light on open quantum systems coupled to stron
gly correlated thermal environments\, these results also provide a princip
led computation of Schwinger-Keldysh observables in gravity and holography
. In particular\, these influence functionals capture both the dissipative
physics of black hole quasinormal modes\, as well as that of the fluctuat
ions encoded in outgoing Hawking quanta\, and interactions between them.\n
\n\nThis talk will be based on https://arxiv.org/abs/2004.02888\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shamik Banerjee (IOP\, Bhubaneswar)
DTSTART;VALUE=DATE-TIME:20200429T093000Z
DTEND;VALUE=DATE-TIME:20200429T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/18
DESCRIPTION:Title: BMS symmetry of celestial OPE\nby Shamik Banerjee (IOP\
, Bhubaneswar) as part of ICTS virtual seminar\n\n\nAbstract\nIn this talk
\, we study the BMS symmetry of the celestial\nOPE of two positive helicit
y gravitons in Einstein theory in four\ndimensions. The celestial OPE is o
btained by Mellin transforming the\nscattering amplitude in the (holomorph
ic) collinear limit. The collinear\nlimit at leading order gives the singu
lar term of the celestial OPE. We\ncompute the first subleading correction
to the OPE by analysing the four\ngraviton scattering amplitude directly
in Mellin space. The subleading\nterm can be written as a linear combinati
on of BMS descendants with the\nOPE coefficients determined by BMS algebra
and the coefficient of the\nleading term in the OPE. This can be done by
defining a suitable BMS\nprimary state. We find that among the descendants
\, which appear at the\nfirst subleading order\, there is one which is cre
ated by holomorphic\nsupertranslation with a simple pole on the celestial
sphere.\n\n This talk is based on https://arxiv.org/abs/2002.00975\n
(https://doi.org/10.1007/JHEP04(2020)130 )\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mark Van Raamsdonk (UBC)
DTSTART;VALUE=DATE-TIME:20200729T033000Z
DTEND;VALUE=DATE-TIME:20200729T043000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/19
DESCRIPTION:Title: Holo-ween\nby Mark Van Raamsdonk (UBC) as part of ICTS
virtual seminar\n\n\nAbstract\nWe argue that given holographic $CFT_1$ in
some state with a dual spacetime geometry $M$\, and given some other holo
graphic $CFT_2$\, we can find states of $CFT_2$ whose dual geometries clos
ely approximate arbitrarily large causal patches of M\, provided that $CFT
_1$ and $CFT_2$ can be non-trivially coupled at an interface. Our $CFT_2$
states are "dressed up as" states of CFT1: they are obtained from the orig
inal $CFT_1$ state by a regularized quench operator defined using a Euclid
ean path-integral with an interface between $CFT_2$ and $CFT_1$. Our resul
ts are consistent with the idea that the precise microscopic degrees of fr
eedom and Hamiltonian of a holographic $CFT$ are only important in fixing
the asymptotic behavior of a dual spacetime\, while the interior spacetime
of a region spacelike separated from a boundary time slice is determined
by more universal properties (such as entanglement structure) of the quant
um state at this time slice. Our picture requires that low-energy gravitat
ional theories related to $CFTs$ that can be non-trivially coupled at an i
nterface are part of the same non-perturbative theory of quantum gravity.\
n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Derek Teaney (SUNY)
DTSTART;VALUE=DATE-TIME:20200805T113000Z
DTEND;VALUE=DATE-TIME:20200805T123000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/20
DESCRIPTION:Title: Transport and hydrodynamics in almost the chiral limit.
\nby Derek Teaney (SUNY) as part of ICTS virtual seminar\n\n\nAbstract\nFi
rst I will briefly review lattice data on the QCD phase transition\, which
shows that real world QCD at the physical pion mass is close enough to th
e chiral limit that the $O_4$ phase transition describes several features
of the QCD crossover. Next I describe the appropriate hydrodynamic theory
in the spontaneously broken chiral limit\, where the pions must be includ
ed in the list of hydrodynamic fields\, and the theory is a prototype for
non-abelian superfluids more generally. In the real world the mass of the
pion is finite\, and thus theory is superfluid like at short distances\, b
ut normal fluid like at long distances. The superfluid modes can be integr
ated out by evaluating the appropriate hydrodynamic loop\, leaving calcula
ble corrections to the transport parameters of the normal fluid. Alternat
ively\, one can develop a kinetic equation for the soft pion modes\, which
can be used to evaluate these corrections. I discuss how these correcti
ons scale near the chiral critical point. Finally\, I point out a few pr
oblems that normal-fluid hydro simulations have in describing the observe
d soft pion yields in heavy ion collisions. I suggest that the superfluid
theory can help to resolve these residual discrepancies with the otherwis
e remarkably successful hydro model.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Raghu Mahajan (IAS\, Princeton)
DTSTART;VALUE=DATE-TIME:20200826T043000Z
DTEND;VALUE=DATE-TIME:20200826T053000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/21
DESCRIPTION:by Raghu Mahajan (IAS\, Princeton) as part of ICTS virtual sem
inar\n\nAbstract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atish Dabholkar (ICTP)
DTSTART;VALUE=DATE-TIME:20200812T093000Z
DTEND;VALUE=DATE-TIME:20200812T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/22
DESCRIPTION:Title: Three Avatars of Mock Modularity\nby Atish Dabholkar (I
CTP) as part of ICTS virtual seminar\n\n\nAbstract\nMock theta functions w
ere introduced by Ramanujan in his famous last letter to Hardy in 1920 but
were properly understood only recently with the work of Zwegers in 2002.
I will describe three manifestations of this apparently exotic mathematics
in three important physical contexts of holography\, topology and dua
lity where mock modularity is essential to exhibit modular symmetries e
xpected from the $AdS_3/CFT_2$ holographic equivalence in quantum grav
ity and the S-duality symmetry of four-dimensional quantum gauge theo
ries. \nIn particular\, I will show that the completion of mock modular f
orms occurring in these contexts satisfy a holomorphic anomaly equation.
This phenomenon can be related to the holomorphic anomaly of the ell
iptic genus of a two-dimensional noncompact supersymmetric sigma model\, a
nd in a simpler context of quantum mechanics to the Atiyah-Patodi-Singer
eta invariant.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pavel Putrov (ICTP)
DTSTART;VALUE=DATE-TIME:20200819T093000Z
DTEND;VALUE=DATE-TIME:20200819T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/23
DESCRIPTION:by Pavel Putrov (ICTP) as part of ICTS virtual seminar\n\nAbst
ract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Netta Englehardt (MIT)
DTSTART;VALUE=DATE-TIME:20200902T133000Z
DTEND;VALUE=DATE-TIME:20200902T143000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/24
DESCRIPTION:by Netta Englehardt (MIT) as part of ICTS virtual seminar\n\nA
bstract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sujay Ashok (IMSc)
DTSTART;VALUE=DATE-TIME:20200916T093000Z
DTEND;VALUE=DATE-TIME:20200916T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/25
DESCRIPTION:by Sujay Ashok (IMSc) as part of ICTS virtual seminar\n\nAbstr
act: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Abhijit Gadde (TIFR)
DTSTART;VALUE=DATE-TIME:20200923T093000Z
DTEND;VALUE=DATE-TIME:20200923T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/26
DESCRIPTION:by Abhijit Gadde (TIFR) as part of ICTS virtual seminar\n\nAbs
tract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nima Arkani-Hamed (IAS\, Princeton)
DTSTART;VALUE=DATE-TIME:20200710T130000Z
DTEND;VALUE=DATE-TIME:20200710T140000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/27
DESCRIPTION:Title: Spacetime\, quantum mechanics and clusterhedra at Infin
ity\nby Nima Arkani-Hamed (IAS\, Princeton) as part of ICTS virtual semina
r\n\n\nAbstract\nElementary particle scattering is perhaps the most basic
physical process in Nature. The data specifying the scattering process def
ines a "kinematic space"\, associated with the on-shell propagation of pa
rticles out to infinity. By contrast the usual approach to computing scatt
ering amplitudes\, involving path integrals and Feynman diagrams\, invokes
auxilliary structures beyond this kinematic space--local interactions in
the interior of spacetime\, and unitary evolution in Hilbert space. This d
escription makes space-time locality and quantum-mechanical unitarity mani
fest\, but hides the extraordinary simplicity and infinite hidden symmetri
es of the amplitudes\,g that have been uncovered over the past thirty year
s. The past decade has seen the emergence of a new picture\, where scatter
ing amplitudes are seen as the answer to an entirely different sort of mat
hematical question involving "positive geometries" directly in the kinemat
ic space\, making surprising connections to total positivity\, combinatori
cs and geometry of the grassmannian\, and cluster algebras. The hidden sym
metries of amplitudes are made manifest in this way\, while locality and
unitarity are seen as derivative notions\, arising from the "factorizing"
boundary structure of the positive geometries. This was first see in the
story of "amplituhedra" and scattering amplitudes in planar N=4 SYM theor
y. In the past few years\, a similar structure has been seen for non-supe
rysmmetric "bi-adjoint" scalar theories with cubic interactions\, in any n
umber of dimensions. The positive geometries through to one-loop order are
given by "cluster polytopes"--generalized associahedra for finite-type cl
uster algebras--with a simple description involving "dynamical evolution"
in the kinematic space. Extending these ideas involves understanding clust
er algebras associated with triangulations of general Riemann surfaces. Th
ese cluster algebras are infinite\, reflecting the infinite action of mapp
ing class group. One of the manifestations of this infinity is that the "g
-vector fan" of the cluster algebra is not space-filling\, making it impos
sible to define cluster polytopes\, and obstructing the connection with po
sitive geometries and scattering amplitudes. Remarkably\, incorporating no
n-cluster variables\, associated with closed loops in the Riemann surfaces
\, suggests a natural way of modding out by the mapping class group\, cano
nically compactifying the cluster complex\, and associating it with "clust
erhedron" polytopes. Clusterhedra are conjectured to exist for all surface
s\, providing the positive geometry in kinematic space for scattering ampl
itudes in the bi-adjoint scalar theory to all loop orders and all orders i
n the 1/N expansion. In this talk I will give an overview of this set of i
deas\, assuming no prior knowledge of scattering amplitudes or cluster a
lgebras. My lectures at the ICTS workshop on scattering amplitudes later t
his month\, will give a systematic\, self-contained exposition of all the
physical and mathematical ideas involved\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vijay Balasubramanian (University of Pennsylvania)
DTSTART;VALUE=DATE-TIME:20200909T130000Z
DTEND;VALUE=DATE-TIME:20200909T140000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/28
DESCRIPTION:by Vijay Balasubramanian (University of Pennsylvania) as part
of ICTS virtual seminar\n\nAbstract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luca Delacretaz (University of Chicago)
DTSTART;VALUE=DATE-TIME:20200930T140000Z
DTEND;VALUE=DATE-TIME:20200930T150000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/29
DESCRIPTION:by Luca Delacretaz (University of Chicago) as part of ICTS vir
tual seminar\n\nAbstract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seok Kim (Seoul National University)
DTSTART;VALUE=DATE-TIME:20201007T093000Z
DTEND;VALUE=DATE-TIME:20201007T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/30
DESCRIPTION:by Seok Kim (Seoul National University) as part of ICTS virtua
l seminar\n\nAbstract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Upamanyu Moitra (TIFR)
DTSTART;VALUE=DATE-TIME:20201014T093000Z
DTEND;VALUE=DATE-TIME:20201014T103000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/31
DESCRIPTION:by Upamanyu Moitra (TIFR) as part of ICTS virtual seminar\n\nA
bstract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edward Witten (IAS\, Princeton)
DTSTART;VALUE=DATE-TIME:20200717T120000Z
DTEND;VALUE=DATE-TIME:20200717T130000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/32
DESCRIPTION:Title: Deformations of JT gravity and matrix models\nby Edward
Witten (IAS\, Princeton) as part of ICTS virtual seminar\n\n\nAbstract\nR
ecently it was shown by Saad\, Shenker\, and Stanford that JT gravity in t
wo dimensions is dual not to any particular quantum system but to a random
ensemble of quantum systems. I will explain that if one deforms JT grav
ity by adding a self-coupling of the scalar field\, the resulting model is
still dual to a random ensemble of quantum systems\, with a different den
sity of energy levels. I will also briefly describe work of Maxfield an
d Turiaci\, who made a similar analysis in two dimensions and related it t
o issues in three-dimensional gravity.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cumrun Vafa (Harvard University)
DTSTART;VALUE=DATE-TIME:20200904T120000Z
DTEND;VALUE=DATE-TIME:20200904T130000Z
DTSTAMP;VALUE=DATE-TIME:20200812T055911Z
UID:ictsvirtual/33
DESCRIPTION:by Cumrun Vafa (Harvard University) as part of ICTS virtual se
minar\n\nAbstract: TBA\n
END:VEVENT
END:VCALENDAR