BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Phil Saad (Stanford)
DTSTART;VALUE=DATE-TIME:20200622T180000Z
DTEND;VALUE=DATE-TIME:20200622T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/1
DESCRIPTION:Title: Some comments about wormholes and factorization\nby Phil Saad (Stanfo
rd) as part of Theoretical Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robert Brandenberger (McGill University)
DTSTART;VALUE=DATE-TIME:20200824T180000Z
DTEND;VALUE=DATE-TIME:20200824T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/2
DESCRIPTION:Title: Inflation and Alternative Early Universe Scenarios in Light of the Swampl
and Constraints\nby Robert Brandenberger (McGill University) as part o
f Theoretical Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Igor Klebanov (Princeton U.)
DTSTART;VALUE=DATE-TIME:20200831T180000Z
DTEND;VALUE=DATE-TIME:20200831T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/3
DESCRIPTION:Title: Breaking of Discrete and Continuous Symmetries in Coupled SYK or Tensor M
odels\nby Igor Klebanov (Princeton U.) as part of Theoretical Physics
Seminars (Kentucky)\n\n\nAbstract\nAbstract : \n\nA large number of Majora
na fermions with interactions coupling four of them at a time can exhibit
interesting quantum dynamics. Models of this kind include the Sachdev-Ye-K
itaev (SYK) model\, where the coefficients of quartic interactions are ran
domly distributed\, and the Tensor models\, where they respect continuous
symmetries. These models exhibit approximate invariance under scaling of t
he time and have power law fall-off of the correlation functions.\n\nIn th
is talk we will discuss a pair of SYK or Tensor models coupled by the quar
tic interactions\, and show that they produce a richer set of phenomena. T
hese include a line of fixed points\, where critical exponents vary along
the line and formally acquire imaginary parts outside it. For one sign of
the coupling constant\, the approximate scale invariance continues to hold
. For the other\, a gap opens in the energy spectrum\, resulting in expone
ntial fall-off of correlation functions. This is indicative of breaking of
a discrete symmetry. Thus\, our quantum mechanical model exhibits dynamic
al phenomena characteristic of higher dimensional quantum field theories.
Furthermore\, the gapped phase of our model may be dual to a certain trave
rsable wormhole in two-dimensional space-time.\n\nThe talk will end with a
similar discussion of a pair of complex SYK models coupled by a quartic i
nteraction which preserves the U(1) x U(1) symmetry. For a range of parame
ters\, this model gives rise to breaking of one of the U(1) symmetries. Th
is is demonstrated via an analysis of the large N Dyson-Schwinger equation
s\, as well as by Exact Diagonalizations of the finite N Hamiltonians.\n\n
Zoom: https://uky.zoom.us/j/97553578130\n
LOCATION:https://researchseminars.org/talk/UKYhepth/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diptarka Das (IIT Kanpur)
DTSTART;VALUE=DATE-TIME:20200909T160000Z
DTEND;VALUE=DATE-TIME:20200909T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/4
DESCRIPTION:Title: Virasoro blocks and quasimodular forms\nby Diptarka Das (IIT Kanpur)
as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nWe analy
se Virasoro blocks as an expansion in heavy exchange dimension. For the on
e point torus block and the four point sphere block each order in the expa
nsion can be written as polynomials in the Eisenstein series. These polyno
mials are further constrained to satisfy a recursion relation\, which can
be re-expressed as a noiseless KPZ equation for the blocks. This structure
can be utilized along with the Zamolodchikov recursions to develop an alg
orithm to construct blocks in the heavy regime. We apply our results to fi
nd the corrections to averaged heavy-heavy-light OPE coefficients.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Partha Mukhopadhyay (Matscience)
DTSTART;VALUE=DATE-TIME:20200916T160000Z
DTEND;VALUE=DATE-TIME:20200916T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/5
DESCRIPTION:Title: A Covariant Lattice and its Application to String Bits\nby Partha Muk
hopadhyay (Matscience) as part of Theoretical Physics Seminars (Kentucky)\
n\n\nAbstract\nWe explore a possibility of constructing lattice theories f
rom a basic principle where lattice is viewed as a restriction of the cont
inuum. This allows us to derive a discrete derivative\, nonlocal on the la
ttice\, that satisfies Liebniz rule. As a result a theorem related to loca
lity follows which states that any local equation in the classical continu
um theory holds true also locally on the lattice. Using this one is able t
o preserve a remnant of all the global and gauge symmetries\, which\, in t
wo dimensions\, can be lifted to include local diffeomorphism and Weyl sym
metries as well. Consequently\, one is able\, for example\, to carry out c
lassical BRST construction of covariant sting bits (for the first time).\n
\nThis lattice derivative is\, in some sense\, similar to SLAC derivative
discussed earlier in the literature. However\, we point out that its actio
n suffers from branch cut ambiguities while acting on Fourier basis. This
may indicate that quantization is not straightforward and may have to be d
one entirely in position space.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Maloney (McGill University)
DTSTART;VALUE=DATE-TIME:20200928T180000Z
DTEND;VALUE=DATE-TIME:20200928T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/6
DESCRIPTION:Title: Gravity from Averaging CFTs\nby Alexander Maloney (McGill University)
as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nI will
explore the idea that certain theories of gravity in Anti-de\nSitter space
are dual to an average over an ensemble of quantum\ntheories\, rather tha
n to a specific quantum theory. I will describe\nan average over Narain
’s family of two-dimensional conformal field\ntheories which describe fr
ee bosons on a torus\, and compute the\npartition function using the Siege
l-Weil formula. The result takes\nthe form of a sum over geometries as on
e would expect in a theory of\ngravity. But the gravitational theory look
s more like a Chern-Simons\ntheory than like Einstein gravity.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sabrina Pasterski (Princeton University)
DTSTART;VALUE=DATE-TIME:20200930T163000Z
DTEND;VALUE=DATE-TIME:20200930T173000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/7
DESCRIPTION:Title: Asymptotic Symmetries & Celestial CFT\nby Sabrina Pasterski (Princeto
n University) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbst
ract\nA universal relationship between asymptotic symmetries\, QFT soft th
eorems\, and low energy observables has reinvigorated attempts at flat spa
ce holography. In this talk we introduce a map from 4d S-matrix elements
to 2d correlators in the putative dual Celestial CFT. In particular\, we
will focus on recent progress towards understanding elements of the IR tri
angle from the perspective of our Celestial CFT.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Petr Horava (Berkeley)
DTSTART;VALUE=DATE-TIME:20201005T180000Z
DTEND;VALUE=DATE-TIME:20201005T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/8
DESCRIPTION:Title: Large N Expansion and Strings Out of Equilibrium\nby Petr Horava (Ber
keley) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nW
e use the methods of large N expansion in non-equilibrium many-body system
s with matrix degrees of freedom\, to identify some universal features of
the anticipated dual description in terms of non-equilibrium string pertur
bation theory. We find that string worldsheets exhibit a triple decomposi
tion\, associated with the forward and backward branches of the Schwinger-
Keldysh time contour\, and with the point at the "end of time" where the t
wo branches meet.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Natalie Klco (U. Washington)
DTSTART;VALUE=DATE-TIME:20201012T180000Z
DTEND;VALUE=DATE-TIME:20201012T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/9
DESCRIPTION:Title: Calculating Nature Naturally\nby Natalie Klco (U. Washington) as part
of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nStudying nature
directly from fundamental degrees of freedom is often computationally lim
ited by \nphysical characteristics of exponentially growing configuration
(Hilbert) spaces with particle number \nand signal-to-noise problems. This
leaves many systems of interest to nuclear and particle physics \nintract
able for known algorithms with current and foreseeable classical computati
onal resources. By \nleveraging their natural capacity to describe entangl
ed many-body states\, the use of quantum systems \nthemselves to form a co
mputational framework is envisioned to be advantageous. In this talk\, I
will \nshare a developing perspective on the entanglement structure of qua
ntum fields and discuss implications \nfor their efficient simulation on q
uantum computational architectures.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ying Zhao (IAS)
DTSTART;VALUE=DATE-TIME:20201014T160000Z
DTEND;VALUE=DATE-TIME:20201014T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/10
DESCRIPTION:Title: The complexity of Petz map\nby Ying Zhao (IAS) as part of Theoretica
l Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yoshitaka Hatta
DTSTART;VALUE=DATE-TIME:20201019T180000Z
DTEND;VALUE=DATE-TIME:20201019T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/11
DESCRIPTION:Title: QCD trace anomaly and the proton mass problem\nby Yoshitaka Hatta as
part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nThe trace
anomaly of QCD is fundamentally important as it imparts mass to hadrons an
d nuclei\, hence to the visible universe. In this talk\, I will introduce
two recent developments regarding the anomaly. In the first part\, I discu
ss the decomposition of the trace anomaly into the quark and gluon parts.
This is a well-defined field theoretical problem that can be addressed in
perturbation theory. In the second part\, I will explain how to measure th
e gluon condensate $\\lange P|F^{\\mu\\nu}F_{\\mu\\nu}|P\\rangle$\, which
constitutes the major part of the trace anomaly\, in near-threshold $J/\\p
si$ production in electron-proton scattering. After giving a review of the
existing theoretical approaches and the experimental situation\, I will e
xplain our new approaches to both photo-production and lepto-production.\n
\nPlease email allicsiva@uky.edu for zoom info if interested in attending\
n
LOCATION:https://researchseminars.org/talk/UKYhepth/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lampros Lamprou (MIT)
DTSTART;VALUE=DATE-TIME:20201021T160000Z
DTEND;VALUE=DATE-TIME:20201021T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/12
DESCRIPTION:Title: Inside the Hologram: The bulk observer's experience\nby Lampros Lamp
rou (MIT) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract
\nI will present a holographic framework for reconstructing the experience
of bulk observers in AdS/CFT. In particular\, I will show how to recover
the proper time and energy distribution measured along bulk worldlines\, d
irectly in the CFT via a universal\, background-independent prescription.
For an observer falling into an eternal AdS black hole\, the proposal reso
lves a conceptual puzzle raised by Marolf and Wall. Notably\, the prescrip
tion does not rely on an external dynamical Hamiltonian or the AdS boundar
y conditions and is\, therefore\, outlining a general framework for the em
ergence of time.\n\nPlease email allicsiva@uky.edu for zoom info if intere
sted in attending\n
LOCATION:https://researchseminars.org/talk/UKYhepth/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michal P. Heller (Max Planck Institute for Gravitational Physics)
DTSTART;VALUE=DATE-TIME:20201026T180000Z
DTEND;VALUE=DATE-TIME:20201026T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/13
DESCRIPTION:Title: Complexity and Conformal Field Theory\nby Michal P. Heller (Max Plan
ck Institute for Gravitational Physics) as part of Theoretical Physics Sem
inars (Kentucky)\n\n\nAbstract\nViewing fundamental physics processes thro
ugh the lenses of quantum information storage and processing is a new fron
tier in gravity and quantum field theory. Much of what we have learnt in t
he past decade builds on the notion of entanglement and its entropy. The l
atter quantifies how hard it is to store a quantum-many body state of inte
rest on a classical computer. Complexity is a new player in the high-energ
y physics context and quantifies how hard it is to prepare a quantum-many
body state using limited resources. Learning from the success story of ent
anglement entropy\, establishing universal results on complexity in two-di
mensional conformal field theories should open many new research direction
s\, including finding a precise gravity dual. I will discuss recent progre
ss on this problem reported in 2005.02415 and 2007.11555 with Flory.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emil Martinec (University of Chicago)
DTSTART;VALUE=DATE-TIME:20201028T160000Z
DTEND;VALUE=DATE-TIME:20201028T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/14
DESCRIPTION:Title: The Return of the String\nby Emil Martinec (University of Chicago) a
s part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nTwo appli
cations of worldsheet string theory illustrate the structure of string the
ory near the threshold of black hole formation. In the first\, we conside
r string probes of horizonless microstate geometries and find that strong
tidal forces cause infalling strings to become trapped\, mimicking the abs
orptive properties of black holes. In the second\, we re-examine the stru
cture of (near) BPS microstates and find a mechanism whereby the geometric
al description breaks down.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mark Van Raamsdonk (UBC)
DTSTART;VALUE=DATE-TIME:20201102T190000Z
DTEND;VALUE=DATE-TIME:20201102T200000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/15
DESCRIPTION:Title: Towards Microscopic Models of Big Bang Cosmology\nby Mark Van Raamsd
onk (UBC) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract
\nIn this talk\, we review an approach to describing cosmological\nphysics
using ordinary AdS/CFT\, where the cosmological physics is the\neffective
description of an end-of-the-world brane which cuts off the\nsecond asymp
totic region of a two-sided black hole. The worldvolume\ngeometry of the b
rane is an FRW big-bang/big-crunch spacetime. In\nfavorable circumstances\
, the brane acts as a Randall-Sundrum Planck\nbrane so that gravity locali
zes. We describe a microscopic construction\nfor such an end-of-the-world
brane with localized gravity in AdS/CFT\,\nstarting from N=4 SYM theory. W
e suggest specific microscopic states of\nN=4 SYM theory that may encode t
he physics in a four-dimensional\ncosmological spacetime.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vishnu Jejjala
DTSTART;VALUE=DATE-TIME:20201104T170000Z
DTEND;VALUE=DATE-TIME:20201104T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/16
DESCRIPTION:Title: Machine learning as a discovery tool in hep-th\nby Vishnu Jejjala as
part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nMachine le
arning provides a new tool for analyzing Big Data and Small Data in mathem
atics and theoretical physics. In this talk\, I discuss two case studies.
The first predicts the volume of the knot complement of hyperbolic knots f
rom the Jones polynomial. The second predicts the masses of baryons such a
s the proton and neutron from knowledge only of the meson spectrum and dis
tinguishes between different composition hypotheses for exotic QCD resonan
ces. Both investigations point to the existence of new analytic formulae.\
n
LOCATION:https://researchseminars.org/talk/UKYhepth/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Al Shapere (Kentucky)
DTSTART;VALUE=DATE-TIME:20201109T190000Z
DTEND;VALUE=DATE-TIME:20201109T200000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/17
DESCRIPTION:Title: Quantum Codes and Conformal Field Theories\nby Al Shapere (Kentucky)
as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nThere i
s a rich web of connections between classical error-correcting codes\, Euc
lidean lattices\, and chiral conformal field theories. I will explain an
analogous relationship between quantum error-correcting codes\, Lorentzian
lattices\, and nonchiral CFTs arising from toroidal compactifications of
strings. Specifically\, I will show how quantum stabilizer codes are embe
dded in the operator algebras of associated Narain CFTs. With respect to
“code” CFTs\, the constraints of modular invariance reduce to simple
algebraic equations. Solving these equations provides many examples of ph
ysically distinct CFTs with the same spectrum\; we also find many solution
s that do not correspond to any code CFT\, and likely do not correspond to
any CFT at all. This exposes a crucial limitation of the conformal boots
trap program – that in general\, a solution of the bootstrap equations i
mplies neither the existence nor the uniqueness of a corresponding CFT.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Raul Briceno (JLab)
DTSTART;VALUE=DATE-TIME:20201111T170000Z
DTEND;VALUE=DATE-TIME:20201111T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/19
DESCRIPTION:Title: Long Range Processes in QCD\nby Raul Briceno (JLab) as part of Theor
etical Physics Seminars (Kentucky)\n\n\nAbstract\nA rich variety of phenom
ena in the Standard Model and its extensions manifest in long-range proces
ses involving bound states of quantum chromodynamics (QCD)\, namely hadron
s. These are processes where intermediate hadronic states propagate over a
long distance\, between electroweak interactions. Examples include virtua
l Compton scattering and double-beta decay. Such processes are at the cusp
of what can be systematically studied given two challenges. First\, these
reactions involve hadrons\, and as a result one must use a non-perturbati
ve tool to access their amplitudes. Currently lattice QCD is the only syst
ematically improvable way we have for doing just this. Second\, lattice QC
D is defined in a finite\, Euclidean spacetime. This introduces its own sp
ecific challenges\, time in purely imaginary in lattice QCD\, and by trunc
ating the space one looses the notion of asymptotic states. In this talk I
explain how these issues can all be resolved systematically for a relativ
ely large kinematic region. In presenting the necessary formalism for doin
g this\, I will summarize recent progress in lattice QCD in order to argue
that the community is up to the challenge.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Barthel (Duke)
DTSTART;VALUE=DATE-TIME:20201116T190000Z
DTEND;VALUE=DATE-TIME:20201116T200000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/20
DESCRIPTION:Title: Entanglement entropy of energy eigenstates follows a universal scaling f
unction\nby Thomas Barthel (Duke) as part of Theoretical Physics Semin
ars (Kentucky)\n\n\nAbstract\nWe consider the entanglement entropies of en
ergy eigenstates in quantum many-\nbody systems. For the typical models th
at allow for a field-theoretical\ndescription of the long-range physics\,
we find that the entanglement entropy of\n(almost) all eigenstates is desc
ribed by a single scaling function. This is\npredicated on the validity of
the weak or strong eigenstate thermalization\nhypothesis (ETH)\, which th
en implies that the scaling functions can be deduced\nfrom subsystem entro
pies of thermal ensembles. The scaling functions describe\nthe full crosso
ver from the groundstate entanglement regime for low energies\nand small s
ubsystem size (area or log-area law) to the extensive volume-law\nregime f
or high energies or large subsystem size. For critical 1d systems\, the\ns
caling function follows from conformal field theory (CFT). We use it to al
so\ndeduce the scaling function for Fermi liquids in d>1 dimensions. These
\nanalytical results are complemented by numerics for large non-interactin
g\nsystems of fermions in d=1\,2\,3 and the harmonic lattice model in d=1\
,2.\nLastly\, we demonstrate ETH for entanglement entropies and the validi
ty of the\nscaling arguments in integrable and non-integrable interacting
spin chains. In\nparticular\, we analyze the XXZ and transverse-field Isin
g models with and\nwithout next-nearest-neighbor interactions.\n\nReferenc
es: arXiv:1905.07760\, arXiv:1912.10045\, arXiv:2010.07265\n
LOCATION:https://researchseminars.org/talk/UKYhepth/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robert De Mello Koch (U. of Witwatersrand)
DTSTART;VALUE=DATE-TIME:20210127T170000Z
DTEND;VALUE=DATE-TIME:20210127T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/21
DESCRIPTION:Title: Scrambling in Yang-Mills Theory\nby Robert De Mello Koch (U. of Witw
atersrand) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstrac
t\nWe study operators with a bare dimension that grows as N^2 in the large
N limit. These operators are labeled by a Young diagram with p long rows\
, as well as a graph\, with p nodes. The dilatation operator describing th
e mixing of these operators defines a Hamiltonian for excitations hopping
on this graph. The scrambling and equilibration of the resulting dynamics
is studied.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Samir Mathur (OSU)
DTSTART;VALUE=DATE-TIME:20210125T190000Z
DTEND;VALUE=DATE-TIME:20210125T200000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/22
DESCRIPTION:by Samir Mathur (OSU) as part of Theoretical Physics Seminars
(Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sean Hartnoll (Stanford)
DTSTART;VALUE=DATE-TIME:20210426T180000Z
DTEND;VALUE=DATE-TIME:20210426T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/24
DESCRIPTION:Title: The classical interior of black holes in holography\nby Sean Hartnol
l (Stanford) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstr
act\nThe exterior dynamics of black holes has played a major role\nin holo
graphic duality\, describing the approach to thermal equilibrium\nof stron
gly coupled media. The interior dynamics of black holes in a\nholographic
setting has\, in contrast\, been largely unexplored. I will\ndescribe rece
nt work investigating the classical interior dynamics of\nvarious holograp
hic black holes. I will discuss the nature of the\nsingularity\, the absen
ce of Cauchy horizons and a new kind of chaotic\nbehavior that emerges in
the presence of charged scalar fields.\n\nPassword: Theory\n
LOCATION:https://researchseminars.org/talk/UKYhepth/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anatoli Polkovnikov (Boston U.)
DTSTART;VALUE=DATE-TIME:20210208T190000Z
DTEND;VALUE=DATE-TIME:20210208T200000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/26
DESCRIPTION:Title: Quantum eigenstates from classical Gibbs distributions\nby Anatoli P
olkovnikov (Boston U.) as part of Theoretical Physics Seminars (Kentucky)\
n\n\nAbstract\nI will discuss how the language of wave functions (state ve
ctors) and associated non-commuting Hermitian operators naturally emerges
from classical mechanics by applying the inverse Wigner-Weyl transform to
the phase space probability distribution and observables. In this language
\, the Schrödinger equation follows from the Liouville equation\, with
ℏ now a free parameter. Classical stationary distributions can be repres
ented as sums over stationary states with discrete (quantized) energies\,
where these states directly correspond to quantum eigenstates. Interesting
ly\, it is now classical mechanics which allows for apparent negative prob
abilities to occupy eigenstates. This correspondence is particularly prono
unced for canonical Gibbs ensembles\, where classical eigenstates satisfy
an integral eigenvalue equation that reduces to the Schrödinger equation
in a saddle-point approximation controlled by the inverse temperature. Thi
s correspondence by showing that some paradigmatic examples such as tunnel
ing\, band structures\, Berry phases\, Landau levels\, level statistics an
d quantum eigenstates in chaotic potentials can be reproduced to a surpris
ing precision from a classical Gibbs ensemble\, without any reference to q
uantum mechanics. At the end I will mention some unpublished results on em
ergence of negative probabilities and associated doubling of the Hilbert s
pace\, which is similar to emergence of spin degrees of freedom.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Soumyadeep Chaudhuri (Hebrew U.)
DTSTART;VALUE=DATE-TIME:20210203T170000Z
DTEND;VALUE=DATE-TIME:20210203T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/27
DESCRIPTION:Title: Thermal order in large N conformal gauge theories\nby Soumyadeep Cha
udhuri (Hebrew U.) as part of Theoretical Physics Seminars (Kentucky)\n\n\
nAbstract\nOur experience with many physical systems tells us that usually
when a symmetry is spontaneously broken at low temperatures\, it is resto
red upon increasing the temperature sufficiently. The abundance of such s
ystems raises the question of whether this is a universal feature of all q
uantum systems. In this talk\, I will present examples of (3+1)-dimensiona
l non-supersymmetric large N gauge theories which demonstrate violations o
f the above feature. I will argue that in the N tending to infinity limit\
, these theories have conformal manifolds which survive under all loop cor
rections to the beta functions of the couplings. I will show that under ce
rtain conditions\, a subset of points on such a conformal manifold demonst
rates the spontaneous breaking of a global symmetry at all nonzero tempera
tures. Furthermore\, I will demonstrate that this symmetry breaking is acc
ompanied by the Higgsing of a subset of gauge bosons leading the system to
be in a persistent Brout-Englert-Higgs phase.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roberto Emparan (U. of Barcelona)
DTSTART;VALUE=DATE-TIME:20210210T170000Z
DTEND;VALUE=DATE-TIME:20210210T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/28
DESCRIPTION:Title: Quantum BTZ black hole\nby Roberto Emparan (U. of Barcelona) as part
of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nThe study of qu
antum effects on black holes including their gravitational backreaction is
an important but notoriously hard problem. I will begin by reviewing how
the framework of braneworld holography allows to solve it for strongly-cou
pled quantum conformal fields. Then I will describe a holographic construc
tion of quantum rotating BTZ black holes (quBTZ) using an exact dual four-
dimensional bulk solution. Besides yielding the quantum-corrected geometry
and the renormalized stress tensor of quBTZ\, we use it to show that the
quantum black hole entropy\, which includes the entanglement of the fields
outside the horizon\, rather non-trivially satisfies the first law of the
rmodynamics\, while the Bekenstein-Hawking-Wald entropy does not.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ramis Movassagh (MIT-IBM)
DTSTART;VALUE=DATE-TIME:20210217T170000Z
DTEND;VALUE=DATE-TIME:20210217T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/29
DESCRIPTION:Title: Constructing quantum codes from any classical code and their embedding i
n ground space of local Hamiltonians\nby Ramis Movassagh (MIT-IBM) as
part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nWe introduc
e a framework for constructing a quantum error correcting code from any cl
assical error correcting code. This includes CSS codes and goes beyond the
stabilizer formalism to allow quantum codes to be constructed from classi
cal codes that are not necessarily linear or self-orthogonal. We give an a
lgorithm that explicitly constructs quantum codes with linear distance and
constant rate from classical codes with a linear distance and rate. As il
lustrations for small size codes\, we obtain Steane's 7−qubit code uniqu
ely from Hamming's [7\,4\,3] code\, and obtain other error detecting quant
um codes from other explicit classical codes of length 4 and 6. Motivated
by quantum LDPC codes and the use of physics to protect quantum informatio
n\, we introduce a new 2-local frustration free quantum spin chain Hamilto
nian whose ground space we analytically characterize completely. By mappin
g classical codewords to basis states of the ground space\, we utilize our
framework to demonstrate that the ground space contains explicit quantum
codes with linear distance. This side-steps the Bravyi-Terhal no-go theore
m because our work allows for more general quantum codes beyond the stabil
izer and/or linear codes. We hesitate to call this an example of {\\it sub
space} quantum LDPC code with linear distance.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aninda Sinha (IISc\, Bangalore)
DTSTART;VALUE=DATE-TIME:20210224T143000Z
DTEND;VALUE=DATE-TIME:20210224T153000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/30
DESCRIPTION:Title: Crossing symmetric dispersion relations in QFTs and CFTs\nby Aninda
Sinha (IISc\, Bangalore) as part of Theoretical Physics Seminars (Kentucky
)\n\n\nAbstract\nI will discuss crossing symmetric dispersion relations in
QFTs and CFTs. I will talk about connections with Polyakov’s 1974 work\
, the crossing symmetric Polyakov-Mellin bootstrap\, and connections with
fixed-t dispersion relations. I will also talk about generalized Froissart
bounds in QFTs which follow from this approach.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ismail Zahed (SUNY\, Stony Brook)
DTSTART;VALUE=DATE-TIME:20210222T190000Z
DTEND;VALUE=DATE-TIME:20210222T200000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/31
DESCRIPTION:Title: Reggeized scattering\, entanglement and chaos using AdS/CFT\nby Isma
il Zahed (SUNY\, Stony Brook) as part of Theoretical Physics Seminars (Ken
tucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Greg Kaplanek (McMaster University)
DTSTART;VALUE=DATE-TIME:20210308T190000Z
DTEND;VALUE=DATE-TIME:20210308T200000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/32
DESCRIPTION:Title: Hot qubits on the horizon\nby Greg Kaplanek (McMaster University) as
part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nPerturbati
on theory for gravitating quantum systems tends to\nfail at very late time
s (a type of perturbative breakdown known as\nsecular growth). We argue th
at gravity is best treated as a\nmedium/environment in such situations\, w
here reliable late-time\npredictions can be made using tools borrowed from
quantum optics. To\nshow how this works\, we study the explicit example o
f a qubit hovering\njust outside the event horizon of a Schwarzschild blac
k hole (coupled to\na real scalar field) and reliably extract the late-tim
e behaviour for\nthe qubit state. At very late times\, the so-called Unruh
-DeWitt detector\nis shown to asymptote to a thermal state at the Hawking
temperature.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shai Chester (Weizmann Institute)
DTSTART;VALUE=DATE-TIME:20210310T170000Z
DTEND;VALUE=DATE-TIME:20210310T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/33
DESCRIPTION:Title: Derivation of AdS/CFT for Vector Models\nby Shai Chester (Weizmann I
nstitute) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract
\nWe derive an explicit map between the singlet sector of the free and cri
tical O(N) and U(N) vector models in any spacetime dimension above two and
to all orders in 1/N\, and a bulk higher spin theory in anti-de Sitter sp
ace in one higher dimension. For the boundary theory\, we use the bilocal
formalism of Jevicki et al to restrict to the singlet sector of the vector
model. The bulk theory is defined from the boundary theory via our mappin
g and is a consistent quantum higher spin theory with a well defined actio
n. Our mapping relates bilocal operators in the boundary theory to higher
spin fields in the bulk\, while single trace local operators in the bounda
ry theory are related to boundary values of higher spin fields.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Toby Wiseman (Imperial College\, London)
DTSTART;VALUE=DATE-TIME:20210315T180000Z
DTEND;VALUE=DATE-TIME:20210315T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/34
DESCRIPTION:Title: Quantum black holes on the lattice\nby Toby Wiseman (Imperial Colleg
e\, London) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstra
ct\nHolography apparently relates certain quantum field theories to quantu
m\ntheories of gravity. The original instance of this is Maldacena's\ndual
ity between maximally supersymmetric gauge theories and type II\nstring th
eory in the presence of D-branes. In the ’t Hooft limit\, and at\napprop
riate temperatures\, the dual to the gauge theory is described by\ncertain
black holes (or rather black p-branes). This allows the\nremarkable oppor
tunity to perform calculations of quantum black holes\nthrough the equival
ent gauge theory\, and to check the consistency of\nholographic duality. I
will discuss such calculations\, and the progress\nthat has been made ove
r the last decade in showing that the predicted\ngravity behaviour does in
deed emerge from thermal gauge theory.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pranjal Nayak (U. of Geneva)
DTSTART;VALUE=DATE-TIME:20210324T160000Z
DTEND;VALUE=DATE-TIME:20210324T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/35
DESCRIPTION:Title: Quantum ergodicity and Euclidean Wormholes\nby Pranjal Nayak (U. of
Geneva) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\n
For a generic quantum-many-body system\, quantum ergodicity is defined as
the limit in which the spectrum of the system resembles that of a random m
atrix theory (RMT) in the corresponding symmetry class. In this talk I wil
l describe the correlation functions in the ergodic limit\, making use of
the causal symmetry breaking to construct an EFT describing the relevant u
niversal late-time dynamics: the ramp and the plateau. I will also discuss
the bulk interpretation of these results in terms of Euclidean wormholes.
\n
LOCATION:https://researchseminars.org/talk/UKYhepth/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nabil Iqbal (Durham U.)
DTSTART;VALUE=DATE-TIME:20210329T180000Z
DTEND;VALUE=DATE-TIME:20210329T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/36
DESCRIPTION:Title: Mean string field theory\nby Nabil Iqbal (Durham U.) as part of Theo
retical Physics Seminars (Kentucky)\n\n\nAbstract\nJust as conventional gl
obal symmetries result in a conserved particle number\, higher-form global
symmetries are associated with a conserved density of higher dimensional
objects\, such as strings or branes. Many well-known systems possess such
symmetries. I will present an overview of the applications of such symmetr
ies and discuss the prospect of using them to enlarge the usual Landau cla
ssification of the phases of matter. I will then describe the construction
of a continuum Landau-Ginzburg theory to describe the spontaneous breakin
g of a higher-form symmetry. As the order parameter is an operator that cr
eates a string\, the framework can be thought of as a kind of "mean string
field theory" that provides a non-perturbative description where effectiv
e strings can be created and destroyed. I will argue that many aspects of
higher form symmetries — including the phase structure\, the behavior of
line operators\, and the dynamics of Goldstone modes — can be transpare
ntly understood in this framework.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dan Carney (UMIACS)
DTSTART;VALUE=DATE-TIME:20210412T180000Z
DTEND;VALUE=DATE-TIME:20210412T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/37
DESCRIPTION:Title: Quantum limits to measurement and dark matter detection\nby Dan Carn
ey (UMIACS) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstra
ct\nIf dark matter exists\, the only way it is guaranteed to couple to vis
ible matter is through gravity. Trying to directly detect dark matter in a
terrestrial laboratory through this coupling would be very difficult due
to the weakness of gravity. However\, it has recently been suggested that
an array of quantum-limited mechanical sensors could be constructed to det
ect heavy (roughly Planck-scale) dark matter candidates purely via gravity
. I'll review the basic idea\, some applications to other (non-gravitation
al) dark matter detection\, and some current experimental work.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stanley Brodsky (SLAC)
DTSTART;VALUE=DATE-TIME:20210419T180000Z
DTEND;VALUE=DATE-TIME:20210419T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/38
DESCRIPTION:Title: Color Confinement and Supersymmetric Features of Hadron Physics from Lig
ht-Front Holography\nby Stanley Brodsky (SLAC) as part of Theoretical
Physics Seminars (Kentucky)\n\n\nAbstract\nI will review applications of s
uperconformal algebra\, light-front holography\, and an extended form of c
onformal symmetry to hadron spectroscopy and dynamics. QCD is not supersy
mmetrical in the traditional sense -- the QCD Lagrangian is based on quark
and gluonic fields -- not squarks nor gluinos. However\, its hadronic eig
ensolutions conform to a representation of superconformal algebra\, reflec
ting the underlying conformal symmetry of chiral QCD. The eigensolutions o
f superconformal algebra provide a unified Regge spectroscopy of meson\, b
aryon\, and tetraquarks of the same parity and twist as equal-mass members
of the same 4-plet representation with a universal Regge slope. The pion
$q \\bar q$ eigenstate is composite but yet has zero mass for $m_q=0.$ Lig
ht-Front Holography also predicts the form of the nonperturbative QCD run
ning coupling: $\\alpha_s(Q^2) \\propto \\exp{-{Q^2/4 \\kappa^2}}$\, in
agreement with the effective charge determined from measurements of the B
jorken sum rule. One also obtains viable predictions for tests of hadron
dynamics such as spacelike and timelike hadronic form factors\, structure
functions\, distribution amplitudes\, and transverse momentum distribution
s. The combined approach of light-front holography and superconformal alge
bra also provides insight into the origin of the QCD mass scale and color
confinement.\n\nPassword: Theory\n
LOCATION:https://researchseminars.org/talk/UKYhepth/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arjun Kar (UBC)
DTSTART;VALUE=DATE-TIME:20210331T160000Z
DTEND;VALUE=DATE-TIME:20210331T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/39
DESCRIPTION:Title: A hierarchy of complexity growth from integrability and chaos\nby Ar
jun Kar (UBC) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbst
ract\nQuantum complexity has been conjectured to be relevant for black hol
e interiors. In particular\, Susskind has conjectured a generic form of c
omplexity growth and saturation for maximally chaotic systems like black h
oles. Using geodesic complexity techniques\, we study the complexity of t
ime evolution in free\, integrable\, and chaotic systems with N degrees of
freedom. We demonstrate that the growth rate of this complexity is relat
ed to more familiar properties of physical theories like 1) the existence
of creation/annihilation operators and 2) smeared thermal two-point functi
ons. Using these properties\, we find that the complexity saturates in fr
ee\, integrable\, and chaotic theories at time scales which are on the ord
er of N^{1/2}\, polynomial in N\, and exponential in N\, respectively. Ou
r results in the free theory improve an existing bound in the complexity t
heory literature\, and our results in chaotic theories are based only on c
oarse properties of the spectrum and eigenstates.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Victor Gorbenko
DTSTART;VALUE=DATE-TIME:20210407T160000Z
DTEND;VALUE=DATE-TIME:20210407T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/40
DESCRIPTION:Title: On QFT in de Sitter\nby Victor Gorbenko as part of Theoretical Physi
cs Seminars (Kentucky)\n\n\nAbstract\nI will discuss the tools we are deve
loping to calculate correlation functions of primordial inflationary pertu
rbations. In this talk we will focus on the limit where gravitational exci
tations are neglected and the cosmological spacetime is assumed to be exac
tly de Sitter. Even in this simplifying limit\, which corresponds to a Qua
ntum Field Theory on a de Sitter background\, very few examples of explici
t analytic calculations exist and little is known about basic properties o
f the correlators. I will show that for any dS QFT there exists a theory f
ormulated in a Euclidean Anti-de SItter space and which reproduces all the
correlation functions. This leads to major technical simplifications and
allows to demonstrate various analytic properties of the cosmological obse
rvables. Understanding of these properties has both phenomenological appli
cations in inflation\, as well as provides some hints about more fundament
al description for cosmological spacetimes.\n\nPasscode\, if needed: 1036
20\n
LOCATION:https://researchseminars.org/talk/UKYhepth/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrei Alexandru
DTSTART;VALUE=DATE-TIME:20210428T160000Z
DTEND;VALUE=DATE-TIME:20210428T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/41
DESCRIPTION:Title: Quantum computing for bosonic fields\nby Andrei Alexandru as part of
Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nAs universal quant
um computers move from theoretical devices towards concrete\nrealizations\
, albeit still quite experimental\, there is a lot of interest in\nunderst
anding whether outstanding problems in nuclear physics\, like real-time\nd
ynamics and bulk properties of nuclear matter\, could be solved using thes
e \nmachines. For these applications we need to represent in hardware quan
tum field \ntheories for both fermionic and bosonics degrees of freedom. D
iscretized fermionic \nfields can be represented fully since they map natu
rally onto qbits. On the other \nhand bosonic degrees of freedom--which ev
en for discretized fields require an \ninfinite dimensional Hilbert space
at each site--require a truncation. In this \ntalk I discuss two direction
s we investigated to address this problem: using \ndiscrete subsets to rep
resent gauge degrees of freedom\, or truncations in a dual \nspace that th
at preserve the original symmetries of the theory. As test-cases \nfor the
se ideas we use pure-gauge QCD and the sigma-model.\n\nPassword: 146625\n
LOCATION:https://researchseminars.org/talk/UKYhepth/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Masanori Hanada (Surrey U.)
DTSTART;VALUE=DATE-TIME:20210414T160000Z
DTEND;VALUE=DATE-TIME:20210414T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/42
DESCRIPTION:Title: Large-N limit as a second quantization\nby Masanori Hanada (Surrey U
.) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nIn ga
uge/gravity duality\, the information regarding the gravitational geometry
(e.g.\, black hole and smooth exterior geometry) has to be encoded in gau
ge theory. Clearly\, the color degrees of freedom (matrix degrees of freed
om) should play the key role\, because the duality can hold even when the
gauge theory side is a matrix model. In this talk\, I will suggest a simpl
e way of encoding the geometry to matrices\, along the line of Witten's wo
rk on the effective action of D-branes and strings\, and the Matrix Theory
conjecture by Banks\, Fischler\, Shenker and Susskind. Roughly speaking\,
eigenvalues of matrices can be identified with the location of the D-bran
e probe or extended objects such as black hole. \n\nActually there is a fa
mous argument against such simple interpretation advocated by Polchinski i
n 1998. His argument used generic properties of large-N gauge theory to sh
ow that the ground-state wave function delocalizes at large N\, leading to
a conflict with the locality in the bulk geometry. We show that this argu
ment is not correct: the ground-state wave function does not delocalize\,
and there is no conflict with the locality of the bulk geometry. In order
to understand how the old argument fails\, recently-discovered connection
between color confinement and Bose-Einstein condensation is useful. This c
onfinement-BEC connection has a striking consequence: in the SU(N) gauge t
heory\, there is a partially-deconfined phase in which an SU(M)-subgroup i
s deconfined. Partial deconfinement\, combined with the "eigenvalue = loca
tion" picture\, provides us with a natural scenario to realize the idea in
BFSS Matrix Theory conjecture --- extended objects\, such as black hole\,
are realized as bound states of D-branes and strings\, that look like non
-commutative blocks in big matrices --- in the Maldacena-type gauge/gravit
y duality. In the large-N limit\, various many-body states can be realized
by considering block-diagonal matrix configurations\, similarly to the BF
SS proposal. Therefore\, the large-N limit of gauge theory can be interpre
ted as the second quantization of the gravity side. \n\nIf time permits\,
we will discuss how we might be able to check this proposal quantitatively
\, via classical or quantum simulations.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Murat Kologlu (Oxford)
DTSTART;VALUE=DATE-TIME:20210421T160000Z
DTEND;VALUE=DATE-TIME:20210421T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/43
DESCRIPTION:Title: Holographic correlators at finite temperature\nby Murat Kologlu (Oxf
ord) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nWe
consider weakly-coupled QFT in AdS at finite temperature. We compute the h
olographic thermal two-point function of scalar operators in the boundary
theory. We present analytic expressions for leading corrections due to loc
al quartic interactions in the bulk\, with an arbitrary number of derivati
ves and for any number of spacetime dimensions. The solutions are fixed by
judiciously picking an ansatz and imposing consistency conditions. The co
nditions include analyticity properties\, consistency with the operator pr
oduct expansion\, and the Kubo-Martin-Schwinger condition. For the case wi
thout any derivatives we show agreement with an explicit diagrammatic comp
utation. The structure of the answer is suggestive of a thermal Mellin amp
litude. Additionally\, we derive a simple dispersion relation for thermal
two-point functions which reconstructs the function from its discontinuity
.\n\nPassword: 496169\n
LOCATION:https://researchseminars.org/talk/UKYhepth/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Keh-Fei Liu (Kentucky)
DTSTART;VALUE=DATE-TIME:20210503T180000Z
DTEND;VALUE=DATE-TIME:20210503T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/44
DESCRIPTION:Title: Hadron Cosmological Constant and Parton Degrees of Freedom\nby Keh-F
ei Liu (Kentucky) as part of Theoretical Physics Seminars (Kentucky)\n\nAb
stract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Johanna Erdmenger
DTSTART;VALUE=DATE-TIME:20210505T160000Z
DTEND;VALUE=DATE-TIME:20210505T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/45
DESCRIPTION:Title: Complexity and modular flows: Relating quantum information\, quantum fie
ld theory and gravity\nby Johanna Erdmenger as part of Theoretical Phy
sics Seminars (Kentucky)\n\n\nAbstract\nI present recent work of our group
on realizing computational complexity in conformal field theories in view
of relating it holographically to complexity proposals in AdS gravity. Ga
tes and cost functions in the CFT are introduced and used for a complexity
definition based on geometric actions on Virasoro and Kac-Moody orbits. W
e discuss a relation to the Euler-Arnold approach in Hamiltonian dynamics.
In a complementary project\, we developed a new method for evaluating mod
ular flows for 1+1-dimensional chiral fermions\, working directly from the
resolvent in complex analysis. Both projects provide new ingredients for
exploring the connection between spacetime and entanglement.\n\nTalk based
on 2004.03619 and 2008.07532\n\nPassword: 489528\n
LOCATION:https://researchseminars.org/talk/UKYhepth/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shreya Vardhan (MIT)
DTSTART;VALUE=DATE-TIME:20210519T160000Z
DTEND;VALUE=DATE-TIME:20210519T170000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/46
DESCRIPTION:Title: An equilibrium approximation for quantum-informational observables in qu
antum many-body systems and gravity\nby Shreya Vardhan (MIT) as part o
f Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nI will explain an
approximation method that gives a simple universal expression for the Ren
yi entropies of an equilibrated pure state in a chaotic quantum many-body
system. This expression is independent of the details of the initial state
and hence reflects thermalization\, while also being manifestly consisten
t with unitarity. I will discuss how applying this method to models of eva
porating black holes leads to a derivation of replica wormholes\, which ha
ve recently been used to address the information loss paradox in these mod
els. More generally\, this approach elucidates the role played by Euclidea
n path integrals in calculations of time-evolved Renyi entropies. It also
helps address the question of whether an average over theories is needed i
n order to explain results from replica wormholes. I will also comment on
work in progress on applications of this approximation method to other qua
ntum-informational quantities.\n\nPassword: 801404\n
LOCATION:https://researchseminars.org/talk/UKYhepth/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Allic Sivaramakrishnan (Caltech)
DTSTART;VALUE=DATE-TIME:20221026T163000Z
DTEND;VALUE=DATE-TIME:20221026T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/47
DESCRIPTION:Title: On-shell Correlators and Color-Kinematics Duality in Curved Spacetimes\nby Allic Sivaramakrishnan (Caltech) as part of Theoretical Physics Sem
inars (Kentucky)\n\n\nAbstract\nIn this talk\, we present progress towards
generalizing on-shell kinematics and color-kinematics duality to curved s
pacetimes. First\, we define a perturbatively calculable quantity—the on
-shell correlator—which furnishes a unified description of particle dyna
mics in curved spacetime. Specializing to the cases of flat and anti-de Si
tter space\, on-shell correlators coincide precisely with on-shell scatter
ing amplitudes and boundary correlators respectively. We then introduce a
notion of on-shell kinematics for symmetric spaces in which the correspond
ing on-shell momenta are built from isometry generators. Using this isomet
ric language in AdS\, we compute scalar correlators and give a field-theor
etic derivation of color-kinematics duality for the nonlinear sigma model.
Finally\, we comment on possible extensions to spacetimes without symmetr
y.\n\nZoom: https://uky.zoom.us/j/86707156638?pwd=VUNFUUl0cmxGMVArNXpVTTV1
MGQ0QT09\n
LOCATION:https://researchseminars.org/talk/UKYhepth/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Scott Collier (Princeton)
DTSTART;VALUE=DATE-TIME:20221102T163000Z
DTEND;VALUE=DATE-TIME:20221102T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/48
DESCRIPTION:Title: Emergent Averaging in Large-$N$ Holography\nby Scott Collier (Prince
ton) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nAbs
tract: In recent years\, a new holographic paradigm has emerged in which s
imple theories of gravity in low dimensions are dual to statistical ensemb
les of quantum mechanical systems rather than particular quantum systems.
This is a conceptual departure from the conventional holographic paradigm\
, particularly as realized in string theory. A hallmark of such averaged h
olographic dualities is the non-factorization of multi-boundary observable
s due to the presence of Euclidean wormholes in the bulk gravitational the
ory. However\, more realistic holographic dualities in higher dimensions a
re not expected to fundamentally involve microscopic averaging. Neverthele
ss\, there are apparently contributions to the semiclassical gravitational
path integral that are associated with averaging in the boundary theory.
In this talk I will attempt to reconcile these perspectives by elucidating
the emergence of averaging in two different models based on recent works
of mine: one top-down\, the other bottom-up. In both cases\, averaging of
boundary degrees of freedom is an emergent phenomenon associated with the
expansion around the semiclassical limit.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tadashi Takayanagi (Kyoto U)
DTSTART;VALUE=DATE-TIME:20221104T000000Z
DTEND;VALUE=DATE-TIME:20221104T013000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/49
DESCRIPTION:Title: CFT Dual of $dS_3$ and Pseudo Entropy\nby Tadashi Takayanagi (Kyoto
U) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nWe pr
opose a holographic duality for gravity on a three-\ndimensional de Sitter
space. This is essentially given by a $k=-2$ limit\nof SU(2) WZW model. W
e show that this proposal reproduces the expected\nfree energy in de Sitte
r gravity. We also analyze the geodesic length in\nthe three dimensional d
e Sitter spacetime and argue that it is\ninterpreted as holographic pseudo
entropy. We will also discuss a time-\nlike entanglement entropy in AdS/C
FT which shares a similar property in\nterms of pseudo entropy.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nima Lashkari (Purdue)
DTSTART;VALUE=DATE-TIME:20221111T173000Z
DTEND;VALUE=DATE-TIME:20221111T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/50
DESCRIPTION:Title: Exact RG yields cMERA\nby Nima Lashkari (Purdue) as part of Theoreti
cal Physics Seminars (Kentucky)\n\n\nAbstract\nWe study the exact renormal
ization group (ERG) of the free O(N) vector model using a generalized smoo
th regulator that modifies the dispersion relation and suppresses the ultr
aviolet modes. We show that the ERG flow for the wave-functionals leads to
a unitary flow that includes\, as a special case\, the continuous multi-s
cale renormalization (cMERA) network. We discuss tensor network renormaliz
ation and the approximate quantum error correction code in RG.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Damian Galante (Kings College (London))
DTSTART;VALUE=DATE-TIME:20221116T173000Z
DTEND;VALUE=DATE-TIME:20221116T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/51
DESCRIPTION:Title: De Sitter horizons & holography\nby Damian Galante (Kings College (L
ondon)) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\n
An inertial observer in de Sitter spacetime is always surrounded by a cosm
ological event horizon. This horizon shares some similarities with the bla
ck hole event horizon\, which suggests the idea of using tools from hologr
aphy to understand its microscopic nature. In this talk\, I will describe
some probes of the cosmological horizon that differ from those of black ho
les and comment on possible holographic interpretations of such results.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atish Dabholkar (ICTP Trieste)
DTSTART;VALUE=DATE-TIME:20221130T170000Z
DTEND;VALUE=DATE-TIME:20221130T183000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/52
DESCRIPTION:Title: Quantum Entanglement in String Theory\nby Atish Dabholkar (ICTP Trie
ste) as part of Theoretical Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Zhiboedov (Harvard)
DTSTART;VALUE=DATE-TIME:20220928T163000Z
DTEND;VALUE=DATE-TIME:20220928T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/54
DESCRIPTION:Title: Holographic thermal correlators\nby Alexander Zhiboedov (Harvard) as
part of Theoretical Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sunil Mukhi (IISER (Pune) and IAS)
DTSTART;VALUE=DATE-TIME:20221003T163000Z
DTEND;VALUE=DATE-TIME:20221003T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/55
DESCRIPTION:Title: Classification of Unitary RCFTs with Two Primaries and c < 25\nby Su
nil Mukhi (IISER (Pune) and IAS) as part of Theoretical Physics Seminars (
Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mitch Weaver (Cincinnati)
DTSTART;VALUE=DATE-TIME:20221012T163000Z
DTEND;VALUE=DATE-TIME:20221012T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/56
DESCRIPTION:Title: Mixing local and extended operators: a 2d vertex algebra in 4d N = 2 SCF
Ts\nby Mitch Weaver (Cincinnati) as part of Theoretical Physics Semina
rs (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Prashant Raman (IISC)
DTSTART;VALUE=DATE-TIME:20220921T163000Z
DTEND;VALUE=DATE-TIME:20220921T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/57
DESCRIPTION:Title: Celestial insights into the S-matrix bootstrap\nby Prashant Raman (I
ISC) as part of Theoretical Physics Seminars (Kentucky)\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/UKYhepth/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Larry Yaffe (U. Washington)
DTSTART;VALUE=DATE-TIME:20221031T173000Z
DTEND;VALUE=DATE-TIME:20221031T190000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/58
DESCRIPTION:Title: Higgs/confinement transitions with fundamental representation matter
\nby Larry Yaffe (U. Washington) as part of Theoretical Physics Seminars (
Kentucky)\n\n\nAbstract\nIt has long been known that smooth crossovers bet
ween “Higgs” regimes and “confining” regimes are possible in some
gauge theories with fundamental representation matter\, leading to a notio
n of Higgs/confinement “complementarity”. But the validity\, or other
wise\, of such complementarity can be subtle\, especially in massless phas
es with Goldstone bosons. This talk will examine the presence or absence
of Higgs/confinement phase transitions\, when there are no distinguishing
local order parameters\, in both instructive models and in dense QCD.\n\nZ
oom: https://uky.zoom.us/j/89827733198?pwd=azhrUllxR2xMcDNyanlFMDJ3bWU3dz0
9\n
LOCATION:https://researchseminars.org/talk/UKYhepth/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:K. Narayan (Chennai Maths Institute)
DTSTART;VALUE=DATE-TIME:20230801T190000Z
DTEND;VALUE=DATE-TIME:20230801T203000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/59
DESCRIPTION:Title: de Sitter space\, extremal surfaces and time-entanglement\nby K. Nar
ayan (Chennai Maths Institute) as part of Theoretical Physics Seminars (Ke
ntucky)\n\nLecture held in CP 303.\n\nAbstract\nI will describe extremal s
urfaces in de Sitter space anchored at the future boundary I+. Since such
surfaces do not return\, they require extra data or boundary conditions in
the past (interior). In entirely Lorentzian de Sitter spacetime\, this le
ads to future-past timelike surfaces stretching between I±. Apart from an
overall −i factor (relative to spacelike surfaces in AdS) their areas a
re real and positive. With a no-boundary type boundary condition\, the top
half of these timelike surfaces joins with a spacelike part on the hemisp
here giving a complex-valued area. Motivated by these\, we describe two as
pects of “time-entanglement” in simple toy models in quantum mechanics
. One is based on a future-past thermofield double type state entangling t
imelike separated states\, which leads to entirely positive structures. An
other is based on the time evolution operator and reduced transition ampli
tudes\, which leads to complex-valued entropy. There are close parallels w
ith pseudo-entropy which we will clarify.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sotaro Sugishita (Yukawa Institute)
DTSTART;VALUE=DATE-TIME:20230823T163000Z
DTEND;VALUE=DATE-TIME:20230823T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/60
DESCRIPTION:Title: Dress code for infrared safe scattering in QED\nby Sotaro Sugishita
(Yukawa Institute) as part of Theoretical Physics Seminars (Kentucky)\n\nL
ecture held in CP 303.\n\nAbstract\nWe consider the infrared (IR) aspects
of S-matrix in QED. We will review IR divergences and their relation to th
e asymptotic symmetry in QED\, and introduce the dressed state formalism t
o obtain IR-safe S-matrix elements. We show a generic condition (dress cod
e) for dressed states to obtain IR-safe S-matrix elements\, and explain th
at the dress code can be interpreted as the memory effect and represents t
he superselection rule of asymptotic symmetry.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gautam Mandal (TIFR (Mumbai))
DTSTART;VALUE=DATE-TIME:20230821T180000Z
DTEND;VALUE=DATE-TIME:20230821T193000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/61
DESCRIPTION:Title: A fresh look at the large-N limit of matrix models and holography\nb
y Gautam Mandal (TIFR (Mumbai)) as part of Theoretical Physics Seminars (K
entucky)\n\nLecture held in CP 303.\n\nAbstract\nWe will discuss some know
n subtleties of emergent geometries from large N theories (why they are di
fferent from our normal expectation for a continuum spacetime) and discuss
a way to address them. We will use matrix models as our main example. The
primary tool will be an exact bosonization of nonrelativistic fermions th
at was discovered some time ago.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Spenta Wadia (ICTS-TIFR (Bengalaru))
DTSTART;VALUE=DATE-TIME:20230816T163000Z
DTEND;VALUE=DATE-TIME:20230816T180000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/63
DESCRIPTION:Title: Dynamics of Black Hole Evaporation in 2-dim Gravity\nby Spenta Wadia
(ICTS-TIFR (Bengalaru)) as part of Theoretical Physics Seminars (Kentucky
)\n\nLecture held in CP 303.\n\nAbstract\nWe will discuss the non-equilibr
ium dynamics of a 2-dim black hole coupled to an external bath\, using the
Schwinger-Keldysh formalism. Tracing the evaporation in real time amounts
to solving non-local stochastic differential equations for the BH degrees
of freedom. We describe the fluctuations that characterise the end point
of the evaporation process. This talk is based on arXiv:2210.15579.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lorenz Eberhardt (U. Amsterdam)
DTSTART;VALUE=DATE-TIME:20231018T173000Z
DTEND;VALUE=DATE-TIME:20231018T183000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/64
DESCRIPTION:Title: The Virasoro Minimal String\nby Lorenz Eberhardt (U. Amsterdam) as p
art of Theoretical Physics Seminars (Kentucky)\n\nLecture held in CP 303.\
n\nAbstract\nI will introduce a critical string theory in two dimensions a
nd demonstrate that this theory\, viewed as two-dimensional quantum gravit
y on the worldsheet\, is equivalent to a double-scaled matrix integral\, w
hich provides the holographic description. The worldsheet theory consists
of Liouville CFT with central charge c\\ge 25 coupled to timelike Liouvill
e CFT with central charge 26-c. The double-scaled matrix integral has as i
ts leading density of states the universal Cardy density of primaries in a
two-dimensional CFT\, which gives the theory its name. The talk is based
on joint work with Scott Collier\, Beatrix Mühlmann and Victor Rodriguez.
\n\nTalk is online but we will meet in CP 303 to watch it.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Upamanyu Moitra (ICTP)
DTSTART;VALUE=DATE-TIME:20231117T183000Z
DTEND;VALUE=DATE-TIME:20231117T193000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/65
DESCRIPTION:Title: Entanglement Entropy in String Compactifications\nby Upamanyu Moitra
(ICTP) as part of Theoretical Physics Seminars (Kentucky)\n\nLecture held
in CP 303.\n\nAbstract\nThe finiteness of entanglement entropy in string
theory has crucial implications for the information paradox\, quantum grav
ity\, and holography. In my talk\, I will describe the recent progress mad
e on establishing this finiteness. I will describe the orbifold constructi
on appropriate for analyzing entanglement in string theory\, the tachyonic
divergences that one encounters and how we get a finite and calculable an
swer for the entanglement entropy\, including ten-dimensional string theor
y and compactification to lower dimensions. (Based on works in collaborati
on with Atish Dabholkar)\n
LOCATION:https://researchseminars.org/talk/UKYhepth/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Takuya Yoda (Kyoto U)
DTSTART;VALUE=DATE-TIME:20231101T173000Z
DTEND;VALUE=DATE-TIME:20231101T183000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/66
DESCRIPTION:Title: Toward chaos in string scatterings\nby Takuya Yoda (Kyoto U) as part
of Theoretical Physics Seminars (Kentucky)\n\nLecture held in CP 303.\n\n
Abstract\nRecently\, black holes have come to be regarded as chaotic objec
ts. We can expect that the origin of this black hole chaos is attributed t
o some string dynamics from the viewpoint of the black hole-string corresp
ondence. In this talk\, we present our series of studies aimed at identify
ing the string dynamics which give rise to black hole chaos. The contents
are as follows:\n(1) Transient chaos analysis in string scatterings at tre
e level\n(2) Strategies for computing higher genus corrections: non-trivia
l saddles in string scattering amplitudes\n(3) String-like melon diagrams
exhibiting fractal behavior\n
LOCATION:https://researchseminars.org/talk/UKYhepth/66/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Debarghya Chakraborty (UK)
DTSTART;VALUE=DATE-TIME:20231108T183000Z
DTEND;VALUE=DATE-TIME:20231108T193000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/67
DESCRIPTION:Title: Temperature Dependence of Lanczos Coefficients\nby Debarghya Chakrab
orty (UK) as part of Theoretical Physics Seminars (Kentucky)\n\nLecture he
ld in CP 303.\n\nAbstract\nThere has been a resurgence of interest in the
Lanczos method as an efficient way of describing operator dynamics. The st
arting point is the thermal autocorrelation function that endows the Lancz
os coefficients with temperature dependence. I will describe how the temp
erature dependence of the Lanczos coefficients can be recast as a classica
l integrable system which can be formally solved as an initial value probl
em. I will give examples and discuss potential applications.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Partha Mukhopadhyay (IMSc (Chennai))
DTSTART;VALUE=DATE-TIME:20231213T183000Z
DTEND;VALUE=DATE-TIME:20231213T193000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/68
DESCRIPTION:Title: Construction of Poincaré invariant theories on a lattice\nby Partha
Mukhopadhyay (IMSc (Chennai)) as part of Theoretical Physics Seminars (Ke
ntucky)\n\nLecture held in CP 303.\n\nAbstract\nIn constructing lattice ve
rsions of physical theories\, usually the spacetime symmetries are given u
p. This is because of the use of difference approximation of the derivativ
e operator which does not satisfy Leibniz rule. The same is responsible fo
r the fermion doubling problem and the associated loss of chirality. We in
troduce a non-local lattice derivative\, hereafter to be called logarithmi
c discrete derivative (LDD)\, as it admits a logarithmic expansion in powe
rs of the difference operator and a formal lattice integral (LI) which is
inverse of LDD. The pair (LDD\, LI) can be shown to satisfy the same diffe
rential and integral calculi of the continuum. We demonstrate how the pair
can be used to construct lattice theories with Poincaré invariance. A st
riking property of the resulting model is a local correspondence which say
s that local equations of the continuum theory still hold true on the latt
ice\, site-wise. Although such a construction looks very formal in positio
n space\, in momentum space the action takes a simple form which may allow
for numerical simulations. We show that the same momentum space results c
an also be obtained by using summation\, instead of LI\, by using a techni
que involving finer lattices. Similar concept was earlier arrived at by G.
Bergner while studying SLAC-type non-local derivatives. We explain how LD
D is related to SLAC derivative and indicate how the new understanding of
locality in position space could potentially allow for more effective use
of non-local derivatives in lattice studies. Time permitting\, we shall al
so discus a generalisation of the construction to a class of curved backgr
ounds and another form of the lattice derivative that achieves the same th
ing but takes the form of an inverse sine hyperbolic function.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sandip Trivedi (TIFR - Mumbai)
DTSTART;VALUE=DATE-TIME:20240214T190000Z
DTEND;VALUE=DATE-TIME:20240214T200000Z
DTSTAMP;VALUE=DATE-TIME:20240224T072630Z
UID:UKYhepth/69
DESCRIPTION:Title: Jackiw-Teitleboim Gravity in deSitter Space\nby Sandip Trivedi (TIFR
- Mumbai) as part of Theoretical Physics Seminars (Kentucky)\n\nLecture h
eld in CP 303.\n\nAbstract\nWe canonically quantise Jackiw-Teitleboim gra
vity in de Sitter space\, with particular attention to the problem of time
. Our results suggest an holographic interpretation for global deSitter
space\, in this two dimensional setting.\n
LOCATION:https://researchseminars.org/talk/UKYhepth/69/
END:VEVENT
END:VCALENDAR