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BEGIN:VEVENT
SUMMARY:David Osten (Ludwig Maximilian University/Max-Planck-Institute for
Physics\, Munich)
DTSTART;VALUE=DATE-TIME:20200624T150000Z
DTEND;VALUE=DATE-TIME:20200624T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/1
DESCRIPTION:Title: Current Algebra and Generalised Geometry\nby David Osten (Ludwig M
aximilian University/Max-Planck-Institute for Physics\, Munich) as part of
Theoretical and Mathematical Physics\n\n\nAbstract\nThe first part of the
talk will be a review of T-duality and generalised geometry in string the
ory. Generalised geometry is a generalisation of Riemannian geometry that
captures certain 'non-geometric' backgrounds which are nevertheless well-d
efined in string theory. A convenient characterisation of such backgrounds
is given in terms of the so-called generalised fluxes.\n\nIn the second p
art of the talk I want to discuss the meaning of these generalised fluxes
in the worldsheet theory. There\, they describe a deformation of the canon
ical Poisson structure -- namely the current algebra. Besides applications
to magnetic backgrounds and integrable sigma models which motivated this
work\, the virtue of the deformed current algebra lies in the fact that it
gives clear-cut routes to non-commutative and non-associative interpretat
ions of the generalised flux backgrounds\, to generalisations of T-duality
and to generalisations to M-theory.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Frederic Bruenner (Vienna University of Technology (TU Wien))
DTSTART;VALUE=DATE-TIME:20200708T150000Z
DTEND;VALUE=DATE-TIME:20200708T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/2
DESCRIPTION:Title: Gauge/gravity duality and the phenomenology of hadrons\nby Frederi
c Bruenner (Vienna University of Technology (TU Wien)) as part of Theoreti
cal and Mathematical Physics\n\n\nAbstract\nI will give a pedagogical intr
oduction to aspects of hadronic physics at low energy\, and show how the m
ethodology of gauge/gravity duality may be applied to certain problems ari
sing in this context. As a concrete example\, I will talk about the search
for glueballs\, bound states of gluons predicted by lattice gauge theory.
These states have not been identified unambiguously among the hadrons we
observe in collider experiments\, in part due to the lack of theoretical p
redictions of their decay rates. I will show how gauge/gravity duality can
be used to calculate glueball decay rates\, and discuss potential implica
tions.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jose Alejandro Rosabal (Asia Pacific Center for Theoretical Physic
s\, Pohang)
DTSTART;VALUE=DATE-TIME:20200722T110000Z
DTEND;VALUE=DATE-TIME:20200722T130000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/3
DESCRIPTION:Title: Schwarzschild black hole thermodynamic entropy on a nice slice\nby
Jose Alejandro Rosabal (Asia Pacific Center for Theoretical Physics\, Poh
ang) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nIn thi
s seminar I will present the calculation of the thermodynamic entropy of a
Schwarzschild black hole on a nice slice. This can be seen as a warm up t
o address the calculation of the Von Neumann entropy for two intervals\, t
hat includes a portion of the interior of the black hole\, and the Page cu
rve. In the end I will comment on the relation between this work and some
recent proposal.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikita Kolganov (ITMP MSU\, Moscow)
DTSTART;VALUE=DATE-TIME:20200923T150000Z
DTEND;VALUE=DATE-TIME:20200923T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/4
DESCRIPTION:Title: Constrained modified gravities: generalized unimodular gravity and bey
ond\nby Nikita Kolganov (ITMP MSU\, Moscow) as part of Theoretical and
Mathematical Physics\n\n\nAbstract\nIn my talk\, I will give you a brief
introduction into modified gravity theories\, and then I will proceed to p
articular modified gravity models\, which I'm interested in. Most of the m
odified gravities are equivalent to the General Relativity\, equipped with
some additional degrees of freedom. In our case these d.o.f. are obtained
by the explicit breaking of general covariance by an algebraic constraint
on metric coefficients. I'm going to discuss the covariantization issue o
f such theories\, its duality to well-known k-essence and self-gravitating
media models\, and applications to inflationary cosmology.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gleb Arutyunov (University of Hamburg)
DTSTART;VALUE=DATE-TIME:20200930T150000Z
DTEND;VALUE=DATE-TIME:20200930T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/5
DESCRIPTION:Title: Hamiltonian structures of the spin Ruijsenaars-Schneider models\nb
y Gleb Arutyunov (University of Hamburg) as part of Theoretical and Mathem
atical Physics\n\n\nAbstract\nTBA\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ariel Arza (ITMP MSU\, Moscow)
DTSTART;VALUE=DATE-TIME:20201007T150000Z
DTEND;VALUE=DATE-TIME:20201007T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/6
DESCRIPTION:Title: Production of massive particles from the decay of a free massless fiel
d\nby Ariel Arza (ITMP MSU\, Moscow) as part of Theoretical and Mathem
atical Physics\n\n\nAbstract\nIn this talk we will show\, in a simple toy
model (H=g\\phi\\chi^2)\, how Bose enhancement allows the decay of a massl
ess field into massive particles. It happens due to a parametric resonance
caused by a big energy density of the decaying field. I will show the ins
tability conditions as well as the energy density threshold for the decay
to occur. I will also compute the equivalent of the spontaneous decay rate
.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrei Zotov (Steklov Mathematical Institute RAS)
DTSTART;VALUE=DATE-TIME:20201021T150000Z
DTEND;VALUE=DATE-TIME:20201021T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/7
DESCRIPTION:Title: On double elliptic integrable system: characteristic determinant and M
anakov triple\nby Andrei Zotov (Steklov Mathematical Institute RAS) as
part of Theoretical and Mathematical Physics\n\n\nAbstract\nWe discuss do
uble elliptic integrable systems\, where the dependence on the momenta of
particles is elliptic. These models generalize the relativistic Ruijsenaar
s integrable systems\, which contain trigonometric (exponential) dependenc
e on momenta. A brief review on underlying dualities and interrelations be
tween integrable systems will be given. We explain how to construct a kind
of determinant representation for the known conservation laws. Finally\,
we will see that in the classical case the double elliptic models are natu
rally described by the Manakov L-A-B triple instead of the Lax pair\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mikhail Khlopunov (ITMP\, Moscow State University)
DTSTART;VALUE=DATE-TIME:20201028T150000Z
DTEND;VALUE=DATE-TIME:20201028T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/8
DESCRIPTION:Title: Modification of the radiation definition in odd dimensions\nby Mik
hail Khlopunov (ITMP\, Moscow State University) as part of Theoretical and
Mathematical Physics\n\n\nAbstract\nIn this seminar\, I will discuss modi
fication of the radiation definition for the case of odd-dimensional space
-time. The standard definition of the wave zone fails in odd dimensions\,
due to the violation of the Huygens principle: the signal from an instanta
neous flash of current reaches an observer after an interval of time requi
red for propagation of the signal at the speed of light\, but then the tai
l is observed endlessly\; while in even-dimensional spaces an instant sign
al ends instantly at the observation point. The reason is that the retarde
d Green’s functions of the wave equation in odd dimensions has support l
ocalised not only on the light cone\, but also inside it. I will discuss t
he covariant retarded quantities technique and Rohrlich-Teitelboim definit
ion of the wave zone. Using this definition\, the scalar radiation from a
point-like charge\, moving along the circular trajectory in three and five
-dimensional space-times\, will be computed. The obtained results will be
verified by the calculations of the spectral distributions of the radiated
energy\, which are indifferent to the dimensionality of the space-time. A
lso\, the contributions of the tails to the radiation will be discussed.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Zhiboedov (CERN)
DTSTART;VALUE=DATE-TIME:20201111T150000Z
DTEND;VALUE=DATE-TIME:20201111T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/9
DESCRIPTION:Title: Event shapes\, the light-ray OPE and superconvergence\nby Alexande
r Zhiboedov (CERN) as part of Theoretical and Mathematical Physics\n\n\nAb
stract\nI will describe recent progress in understanding event shapes in c
onformal field theories. Familiar from the description of hadronic events
at colliders\, these observables are computed by matrix elements of the so
-called light-ray operators. Characterizing the light-ray operators in a n
onperturbative setting poses many theoretical challenges. I will describe
some of the recently developed tools to perform computations of conformal
event shapes and illustrate them using N=4 SYM. Finally\, I will explain h
ow via holography some of the basic properties of conformal event shapes l
ead to nontrivial sum rules obeyed by possible UV completions of general r
elativity.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sandipan Kundu (Johns Hopkins University)
DTSTART;VALUE=DATE-TIME:20201118T150000Z
DTEND;VALUE=DATE-TIME:20201118T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/10
DESCRIPTION:Title: Closed strings and weak gravity condition from higher-spin causality<
/a>\nby Sandipan Kundu (Johns Hopkins University) as part of Theoretical a
nd Mathematical Physics\n\n\nAbstract\nI will show that metastable higher
spin particles\, free or interacting\, cannot couple to gravity while pres
erving causality unless there exist higher spin states in the gravitationa
l sector much below the Planck scale. Causality imposes an upper bound on
the mass of the lightest higher spin particle in the gravity sector in ter
ms of quantities in the non-gravitational sector. I will argue that any we
akly coupled UV completion of such a theory must have a gravity sector con
taining infinite towers of asymptotically parallel\, equispaced\, and line
ar Regge trajectories. This implies that the gravity sector has a stringy
structure with an upper bound on the string scale. Another consequence of
this bound is that all metastable higher spin particles in 4d with masses
below the string scale must satisfy a weak gravity condition. Moreover\, t
hese bounds also have surprising implications for large N QCD coupled to g
ravity.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tim Adamo (University of Edinburgh)
DTSTART;VALUE=DATE-TIME:20201125T150000Z
DTEND;VALUE=DATE-TIME:20201125T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/11
DESCRIPTION:Title: Scattering in chiral strong backgrounds\nby Tim Adamo (University
of Edinburgh) as part of Theoretical and Mathematical Physics\n\n\nAbstra
ct\nThere are many reasons to be interested in quantum field theory in the
presence of strong\, non-perturbative background fields\, but surprisingl
y little is known in these scenarios\, especially when compared to trivial
backgrounds. For instance\, the full semi-classical S-matrices of gauge t
heory and gravity are known in a trivial background\, but even for simple
strong backgrounds the tree-level amplitudes of these theories have not be
en computed beyond four-external particles. This raises the question: are
all-multiplicity formulae (and other hallmarks of the study of scattering
amplitudes in recent years) inextricably tied to trivial backgrounds? In t
his talk\, I will demonstrate that for a broad class of chiral backgrounds
in four-dimensions\, we can find all-multiplicity expressions for tree-le
vel scattering amplitudes of gauge theory and gravity which are remarkably
simple and clearly un-related to standard background-coupled field theory
on space-time.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Konstantin Zarembo (Niels Bohr Institute\, Nordita)
DTSTART;VALUE=DATE-TIME:20201202T150000Z
DTEND;VALUE=DATE-TIME:20201202T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/12
DESCRIPTION:Title: Large-N localization and quiver CFT\nby Konstantin Zarembo (Niels
Bohr Institute\, Nordita) as part of Theoretical and Mathematical Physics
\n\n\nAbstract\nThe quiver CFT interpolates between N=4 SYM and N=2 super-
QCD\, and is dual to strings on the AdS5 x S5/Z2 orbifold. Localization of
the path integral in the quiver CFT potentially gives means to test this
duality rigorously. The strong-coupling solution of the localization matri
x model\, which I will describe\, is in the remarkable qualitative agreeme
nt with the holographic dual\, but is not devoid of puzzling features.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fedor Popov (Princeton University)
DTSTART;VALUE=DATE-TIME:20201209T150000Z
DTEND;VALUE=DATE-TIME:20201209T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/13
DESCRIPTION:Title: RG Limit Cycles and "Spooky" Fixed Points in Perturbative QFT\nby
Fedor Popov (Princeton University) as part of Theoretical and Mathematica
l Physics\n\n\nAbstract\nWe study quantum field theories with sextic inter
actions in \n3−ϵ dimensions\, where the scalar fields ϕab form irreduc
ible representations under the O(N)2 or O(N) global symmetry group. We cal
culate the beta functions up to four-loop order and find the Renormalizati
on Group fixed points. In an example of large N equivalence\, the parent O
(N)2 theory and its anti-symmetric projection exhibit identical large N be
ta functions which possess real fixed points. However\, for projection to
the symmetric traceless representation of O(N)\, the large N equivalence i
s violated by the appearance of an additional double-trace operator not in
herited from the parent theory. Among the large N fixed points of this dau
ghter theory we find complex CFTs. The symmetric traceless O(N) model also
exhibits very interesting phenomena when it is analytically continued to
small non-integer values of N. Here we find unconventional fixed points\,
which we call "spooky." They are located at real values of the coupling co
nstants gi\, but two eigenvalues of the Jacobian matrix ∂βi/∂gj are c
omplex. When these complex conjugate eigenvalues cross the imaginary axis\
, a Hopf bifurcation occurs\, giving rise to RG limit cycles. This crossin
g occurs for Ncrit≈4.475\, and for a small range of N above this value w
e find RG flows which lead to limit cycles.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ivo Sachs (Ludwig Maximilian University of Munich)
DTSTART;VALUE=DATE-TIME:20201216T150000Z
DTEND;VALUE=DATE-TIME:20201216T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/14
DESCRIPTION:Title: Loops in Holography\nby Ivo Sachs (Ludwig Maximilian University o
f Munich) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nA
quantum field theory (QFT) in an (Anti-)de Sitter\, (A-)dS space-time can
be characterised by a conformal field theory (CFT) much like the S-matrix
for Minkowski QFT’s. I will review how quantum loops are reflected in C
FT\, both in AdS and dS. The latter has a remote connection to density per
turbations in the Universe.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Domenico Orlando (INFN Turin\, University of Bern)
DTSTART;VALUE=DATE-TIME:20210127T150000Z
DTEND;VALUE=DATE-TIME:20210127T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/15
DESCRIPTION:Title: The O(N) vector model at large charge: EFT\, large N and resurgence\nby Domenico Orlando (INFN Turin\, University of Bern) as part of Theo
retical and Mathematical Physics\n\n\nAbstract\nI will discuss the IR fixe
d point of the O(N) vector model in 3 dimensions (Wilson-Fisher point) in
the framework of the large charge expansion. First I will construct an EFT
valid for any N\, then verify the prediction of the model in the double s
caling limit of large N\, large charge and finally discuss the use of resu
rgence to extend the validity of the EFT to sectors of small charge.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Piotr Tourkine (Paris LPTHE\, CERN)
DTSTART;VALUE=DATE-TIME:20210203T150000Z
DTEND;VALUE=DATE-TIME:20210203T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/16
DESCRIPTION:Title: Scattering from production in 2d\nby Piotr Tourkine (Paris LPTHE\
, CERN) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nIn
this seminar\, I will talk about recent results about a numerical method t
o find unitary S-matrices. The method\, based on works of Atkinson\, was i
nvented in the late 60s and was used as a proof of existence of functions
that satisfy all of the S-matrix axioms in 4d. However\, it was not put in
practical use.\nOur recent results concern the implementation of those me
thods for S-matrices in two dimensions\, using two different iterative sch
emes: a fixed-point iteration and Newton's method. Those schemes iterate t
he unitarity and dispersion relations\, and converge to solutions to the S
-matrix axioms. This numerical strategy provides a solution to the problem
of reconstructing the scattering amplitude starting from a given particle
production probability. \nAfter a general introduction\, the talk will be
focused on how we implemented the algorithms\, what they converge to\, an
d the conditions under which they converge. We will see that the question
of convergence naturally connects to the recent study of the coupling maxi
mization in the two-dimensional S-matrix bootstrap. If time allows\, I'll
also comment on a fractal structure which we observed to be related to the
so-called CDD-ambiguities.\nI'll conclude with possible future directions
.\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Xinan Zhou (Princeton University)
DTSTART;VALUE=DATE-TIME:20210217T150000Z
DTEND;VALUE=DATE-TIME:20210217T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/17
DESCRIPTION:Title: Holographic correlators and emergent Parisi-Sourlas supersymmetry
\nby Xinan Zhou (Princeton University) as part of Theoretical and Mathemat
ical Physics\n\n\nAbstract\nIn this talk\, I will first review the recent
progress in computing holographic four-point correlators in maximally supe
rsymmetric CFTs. I will introduce the so-called Maximally R-symmetry Viola
ting (MRV) limit\, in which the Mellin amplitudes drastically simplify and
become easy to compute. From the MRV limit\, I will show that the full am
plitudes can be reconstructed by using symmetries. This gives a complete a
nswer to all tree-level four-point functions in all three maximally supers
ymmetric backgrounds AdS4xS7\, AdS5xS5\, and AdS7xS4. In the second part o
f my talk\, I will point out that these results have surprising properties
. The Mellin amplitudes exhibit an emergent dimensional reduction structur
e\, which allows them to be expressed in terms of only scalar exchange amp
litudes from lower dimensional spacetimes. I will explain that this dimens
ional reduction structure is closely related to a holographic realization
of the Parisi-Sourlas supersymmetry.\n\nConference id: 923 6907 4572\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ricardo Monteiro (Queen Mary University of London)
DTSTART;VALUE=DATE-TIME:20210224T150000Z
DTEND;VALUE=DATE-TIME:20210224T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/18
DESCRIPTION:Title: Gravity as a double copy of gauge theory\nby Ricardo Monteiro (Qu
een Mary University of London) as part of Theoretical and Mathematical Phy
sics\n\n\nAbstract\nRelations expressing gravity as a "double copy" of gau
ge theory appeared first in string theory\, and have been used to compute
scattering amplitudes in theories of gravity\, with applications to both t
heory and phenomenology. I will discuss how the double copy extends to sol
utions to the equations of motion\, including our best known black hole sp
acetimes\, and how this story connects to the original story for scatterin
g amplitudes.\n\nMeeting ID: 928 8340 6261\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Linus Wulff (Masaryk University)
DTSTART;VALUE=DATE-TIME:20210303T150000Z
DTEND;VALUE=DATE-TIME:20210303T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/19
DESCRIPTION:Title: O(D\,D) and string alpha'-corrections\nby Linus Wulff (Masaryk Un
iversity) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nS
tring theory on a d-dimensional torus features an O(d\,d) symmetry. It has
been suggested that the low-energy effective action can be formulated wit
h a larger O(D\,D) symmetry\, even before putting the theory on a torus. T
his approach\, which goes by the name of Double Field Theory (DFT)\, has p
roven very useful. I will address the problem of constructing higher deriv
ative invariants in this formalism. In agreement with the literature we fi
nd that a quadratic Riemann invariant can be constructed\, which can accou
nt for the first alpha'-correction to the bosonic and heterotic string. Ho
wever\, we find that no cubic or quartic Riemann invariants can be constru
cted. This suggests that the quartic Riemann terms arising at order alpha'
^3 in string theory do not have a DFT embedding.\n\nConference ID: 966 841
5 0220\nPasscode: 995622\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Radu Roiban (Penn State University)
DTSTART;VALUE=DATE-TIME:20210310T150000Z
DTEND;VALUE=DATE-TIME:20210310T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/20
DESCRIPTION:Title: Spinning and spinless two-particle dynamics from gravitational scatte
ring amplitudes\nby Radu Roiban (Penn State University) as part of The
oretical and Mathematical Physics\n\n\nAbstract\nIn the appropriate classi
cal limit\, scattering amplitude-based techniques can yield the classical
interaction of massive bodies at fixed order in the post-Minkowskian expan
sion.\n\nIn this talk we review a framework for the construction of the tw
o-body Hamiltonian for compact binary systems and illustrate it with state
of the art results for both spinning and spinless systems. Throughout we
emphasize structure of gravitational interactions and direct relations bet
ween scattering amplitudes and observables of two-particle dynamics.\n\nMe
eting ID: 933 8672 1535\nPasscode: 122819\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vladimir Rosenhaus (Institute for Advanced Study\, Princeton)
DTSTART;VALUE=DATE-TIME:20210317T150000Z
DTEND;VALUE=DATE-TIME:20210317T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/21
DESCRIPTION:Title: Chaotic scattering with a highly excited string\nby Vladimir Rose
nhaus (Institute for Advanced Study\, Princeton) as part of Theoretical an
d Mathematical Physics\n\n\nAbstract\nMotivated by the desire to understan
d chaos in the S-matrix of string theory\, we study tree level scattering
amplitudes involving highly excited strings. While the amplitudes for scat
tering of light strings have been a hallmark of string theory since its e
arly days\, scattering of excited strings has been far less studied. Recen
t results on black hole chaos\, combined with the correspondence principle
between black holes and strings\, suggest that the amplitudes have a ric
h structure. We review the procedure by which an excited string is formed
by repeatedly scattering photons off of an initial tachyon. We compute the
scattering amplitude of one arbitrary excited string decaying into two ta
chyons\, and study its properties for a generic excited string. We find th
e amplitude is highly erratic as a function of both the precise excited st
ring state and of the tachyon scattering angle.\n\nMeeting ID: 936 3872 06
64\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Paul Heslop (Durham University)
DTSTART;VALUE=DATE-TIME:20210324T150000Z
DTEND;VALUE=DATE-TIME:20210324T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/22
DESCRIPTION:Title: Towards the Virasoro-Shapiro Amplitude in AdS5xS5\nby Paul Heslop
(Durham University) as part of Theoretical and Mathematical Physics\n\n\n
Abstract\nWe propose a systematic procedure for obtaining all single trace
1/2-BPS correlators in N=4 super Yang-Mills corresponding to the four-poi
nt tree-level amplitude for type IIB string theory in AdS5xS5. The underly
ing idea is to compute generalised contact Witten diagrams coming from a 1
0d effective field theory on AdS5xS5 whose coefficients are fixed by the f
lat space Virasoro-Shapiro amplitude up to ambiguities related to commutat
ors of the 10d covariant derivatives which require additional information
such as localisation. We illustrate this procedure by computing stringy co
rrections to the supergravity prediction for all single trace 1/2-BPS corr
elators up to O(α′7)\, and spell out a general algorithm for extending
this to any order in α′.\n\nID: 949 0759 4642\nPasscode: 121781\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Congkao Wen (Queen Mary University of London)
DTSTART;VALUE=DATE-TIME:20210331T150000Z
DTEND;VALUE=DATE-TIME:20210331T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/23
DESCRIPTION:Title: Integrated four-point correlators in N=4 SYM\nby Congkao Wen (Que
en Mary University of London) as part of Theoretical and Mathematical Phys
ics\n\n\nAbstract\nIn this talk\, we will discuss integrated correlators o
f four superconformal primaries in N=4 super Yang-Mills\, that are defined
by integrating over spacetime coordinates of the four-point correlator wi
th certain integration measures. The integrated correlators can be compute
d using supersymmetric localisation\, which are expressed as N-dimensional
matrix-model integrals. We will mostly focus on one of the integrated cor
relators. We find that this integrated correlator can be presented as a la
ttice sum\, which makes manifest the SL(2\, Z) modular invariance of N=4 S
YM. Furthermore\, the integrated correlator obeys a remarkable Laplace-di
fference equation\, which relates the correlator of SU(N) theory with thos
e of SU(N-1) and SU(N+1) theories. The expression allows us to obtain exac
t results of the integrated correlator in various limits. For instance\, i
n perturbation\, the expression is checked to be consistent with known res
ults in the literature\; in the large-N limit\, it is shown to match with
the expected results from string theory due to AdS/CFT duality\n\nMeeting
ID: 946 1044 3637\nPasscode: 074360\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oleg Lunin (SUNY-Albany)
DTSTART;VALUE=DATE-TIME:20210407T150000Z
DTEND;VALUE=DATE-TIME:20210407T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/24
DESCRIPTION:Title: Supergravity excitations of stringy geometries\nby Oleg Lunin (SU
NY-Albany) as part of Theoretical and Mathematical Physics\n\n\nAbstract\n
Motivated by the desire to understand the dynamics of light modes on vario
us gravitational backgrounds\, this talk summarizes recent results concern
ing properties of scalar\, vector\, and tensor excitations of black holes
and integrable stringy geometries.\n\nFor rotating black holes and for cer
tain Wess-Zumino-Witten models\, full separability of all dynamical equati
ons is demonstrated\, and symmetries underlying this property are uncovere
d. For other classes of integrable backgrounds\, the energy spectra of var
ious fields are evaluated\, and the algebraic constructions of the corresp
onding eigenfunctions are presented.\n\nMeeting ID: 973 8330 1111\nPasscod
e: 082472\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Vikman (Institute of Physics of the Czech Academy of Sci
ences\, Prague)
DTSTART;VALUE=DATE-TIME:20210414T150000Z
DTEND;VALUE=DATE-TIME:20210414T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/25
DESCRIPTION:Title: Losing the trace to discover dynamical Newton or Planck constants
\nby Alexander Vikman (Institute of Physics of the Czech Academy of Scienc
es\, Prague) as part of Theoretical and Mathematical Physics\n\n\nAbstract
\nI will discuss our recent work e-Print: 2011.07055. There we showed tha
t promoting the trace part of the Einstein equations to a trivial identit
y results in the Newton constant being an integration constant. Thus\, in
this formulation the Newton constant is a global dynamical degree of freed
om which is also a subject to quantization\, quantum fluctuations and the
Heisenberg uncertainty relations. This is similar to what happens to the
cosmological constant in the unimodular gravity where the trace part of th
e Einstein equations is lost in a different way. I will consider a constra
ined variational formulation of these modified Einstein equations. Then\,
drawing on analogies with the Henneaux-Teitelboim action for unimodular gr
avity\, I will discuss different general-covariant actions resulting in th
ese dynamics. In this approach\, it turned out that the inverse of the dyn
amical Newton constant is canonically conjugated to the Ricci scalar integ
rated over spacetime. Surprisingly\, instead of the dynamical Newton const
ant one can formulate an equivalent theory with a dynamical Planck constan
t. Finally\, I will show that an axion-like field can play a role not only
of the cosmological constant\, as in e-Print: 2001.03169\, but also of th
e Newton constant or even of the Planck constant.\n\nMeeting ID: 953 6604
7713\nPasscode: 353336\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alberto Salvio (University of Rome Tor Vergata)
DTSTART;VALUE=DATE-TIME:20210421T150000Z
DTEND;VALUE=DATE-TIME:20210421T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/26
DESCRIPTION:Title: Models for a vast energy range: particles meet gravity and cosmology<
/a>\nby Alberto Salvio (University of Rome Tor Vergata) as part of Theoret
ical and Mathematical Physics\n\n\nAbstract\nI will discuss models valid o
ver a vast energy range by following 2 strategies. In one approach (bottom
-up) I will illustrate the main phenomenological aspects of a scenario whe
re one adds to the Standard Model 3 right-handed neutrinos and an axion se
ctor. This can account for neutrino oscillations\, dark matter\, baryogeng
esis\, inflation and can also stabilize the electroweak vacuum. In another
\, more ambitious approach\, I will talk about a scenario where all coupli
ngs flow to zero at infinite energy (total asymptotic freedom). The corre
sponding phenomenology of this top-down approach will also be treated.\n\n
Meeting ID: 977 1065 2931\nPasscode: 042219\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Osten (ITMP MSU\, Moscow)
DTSTART;VALUE=DATE-TIME:20210505T150000Z
DTEND;VALUE=DATE-TIME:20210505T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/27
DESCRIPTION:Title: Exceptional world-volume currents and their algebras\nby David Os
ten (ITMP MSU\, Moscow) as part of Theoretical and Mathematical Physics\n\
n\nAbstract\nAfter a short review of exceptional generalised geometry I wi
ll introduce a unified setup for a duality-covariant Hamiltonian formulati
on of world-volume theories of objects in string and M-theory. Based on ht
tps://arxiv.org/abs/2103.03267\n\nMeeting ID: 981 6226 4274\nPasscode: 001
440\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jorge Guillermo Russo (ICREA and University of Barcelona)
DTSTART;VALUE=DATE-TIME:20210512T150000Z
DTEND;VALUE=DATE-TIME:20210512T170000Z
DTSTAMP;VALUE=DATE-TIME:20210514T205010Z
UID:ITMPseminar/28
DESCRIPTION:Title: Thermal correlators in CFT and black holes\nby Jorge Guillermo Ru
sso (ICREA and University of Barcelona) as part of Theoretical and Mathema
tical Physics\n\n\nAbstract\nWe describe the computation of thermal 2-poin
t correlation functions in the black brane AdS5 background dual to 4d CFT'
s at finite temperature for operators of large scaling dimension. This giv
es rise to a formula that matches the expected structure from the OPE. The
thermal 2-point function has an exponentiation property\, whose origin we
explain. We also compute the first correction to the two-point function d
ue to graviton emission\, which encodes the time travel to the black hole
singularity. We will also discuss some interesting features of higher-poin
t functions.\n\nMeeting ID: 919 8499 0422\nPasscode: 268796\n
LOCATION:https://researchseminars.org/talk/ITMPseminar/28/
END:VEVENT
END:VCALENDAR