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BEGIN:VEVENT
SUMMARY:Vladimir Gerdjikov (Varna Free University & Institute of Mathemati
cs and Informatics\, Bulgarian Academy of Sciences)
DTSTART:20231108T100000Z
DTEND:20231108T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/1
DESCRIPTION:Title: Sine-Gordon equation: solitons\, applications\, integrability\nby
Vladimir Gerdjikov (Varna Free University & Institute of Mathematics and
Informatics\, Bulgarian Academy of Sciences) as part of AUTH HEP-TH Semina
rs\n\nLecture held in Theory Seminar Room (4th Floor).\n\nAbstract\nThe si
ne-Gordon equation has been discovered by Bäcklund 1870-ies as the equati
on that describes the surfaces with constant negative curvature. He also p
roposed a method for constructing non-trivial solutions\, which is now kno
wn as the Bäcklund transformation. The interest to this equation was revi
ved in the 1970-ies when it was discovered that it describes phenomena in
nonlinear optics\, and that it can be solved using the inverse scattering
method. I will demonstrate that the inverse scattering method applied to s
ine-Gordon equation can be viewed as generalized Fourier transform. Using
it I will demonstrate that sine-Gordon equation allows a hierarchy of Ham
iltonian structures. In fact it is an infinite-dimensional completely inte
grable Hamiltonian system which allows global action-angle variables.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vladimir Gerdjikov (Varna Free University & Institute of Mathemati
cs and Informatics\, Bulgarian Academy of Sciences)
DTSTART:20231129T100000Z
DTEND:20231129T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/2
DESCRIPTION:Title: Sine–Gordon type equations and generalized Fourier transforms\nb
y Vladimir Gerdjikov (Varna Free University & Institute of Mathematics and
Informatics\, Bulgarian Academy of Sciences) as part of AUTH HEP-TH Semin
ars\n\nLecture held in Theory Seminar Room (4th Floor).\n\nAbstract\nBy Si
ne–Gordon type equations we mean nonlinear evolution equations which\, l
ike the Sine–Gordon equation allow Lax representation. We analyze the ma
pping between the potential q(x\,t) of the Lax operator to the scattering
matrix T(t\,λ) and show that it can be understood as a generalized Fourie
r transform (GFT). The relevant generalizations of the usual exponentials
are expressed in terms of the fundamental analytic solutions of L and are
known as ‘squared solutions‘ of L. Similar analysis is done also for t
he mapping between the time derivatives $q_t (x\, t)$ and $T_t (t\, λ)$.
This mapping also can be interpreted as GFT and uses the same ‘squared s
olutions‘. These expansions allow one to linearize the class of nonlinea
r evolution equations (NLEE)\, solvable by the inverse scattering method f
or L and to derive their fundamental properties: the description of the cl
ass of NLEE and their hierarchies of Hamiltonian structures.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vasilis Spanos (National and Kapodistrian University of Athens)
DTSTART:20231213T100000Z
DTEND:20231213T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/3
DESCRIPTION:Title: Supersymmetric Dark Matter Models\nby Vasilis Spanos (National and
Kapodistrian University of Athens) as part of AUTH HEP-TH Seminars\n\n\nA
bstract\nIn this talk we will revisit models that predict dark matter in t
he context of supersymmetric theories. In particular we will focus on mode
ls that yield neutralino\, gravitino and/or primordial black holes dark ma
tter.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Damianos Iosifidis (University of Tartu)
DTSTART:20240124T120000Z
DTEND:20240124T130000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/4
DESCRIPTION:Title: Hyperhydrodynamics: Imperfect Fluids Emerging from Hypermomentum\n
by Damianos Iosifidis (University of Tartu) as part of AUTH HEP-TH Seminar
s\n\nLecture held in Theory Seminar Room (4th Floor).\n\nAbstract\nWe expl
ore a new action formulation of hyperfluids\, fluids with intrinsic hyperm
omentum. Brown's Lagrangian for a relativistic perfect fluid is generalise
d by incorporating the degrees of freedom encoded in the hypermomentum ten
sor\, namely by including connection-matter couplings. Quite interestingly
\, generic hyperfluids are imperfect\, since hypermomentum induces such ef
fects as bulk and shear viscosities as well as heat fluxes. The various co
efficients that appear in the first order expansion of hydrodynamics can n
ow be deduced from a Lagrangian formulation\, given a geometrical interpre
tation and a suggested microscopic description in terms of hypermomentum.
This connection between hypermomentum and dissipative fluids could shed ne
w light on the physics of relativistic hydrodynamics. The applicability of
the new formalism is demonstrated by exact cosmological solutions.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christos Charmousis (University of Paris-Saclay)
DTSTART:20240207T100000Z
DTEND:20240207T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/5
DESCRIPTION:Title: Black holes with primary hair\nby Christos Charmousis (University
of Paris-Saclay) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nWe will co
nstruct and analyse explicit solutions in scalar tensor theories parametri
sed by two independent charges : their ADM mass and an additional primary
hair associated to a minimally coupled scalar field. When the scalar charg
e is set to zero one obtains a Schwarzschild black hole whereas the primar
y hair\, when switched on gradually changes the black hole solution. A spe
cial relation between the two can even render the solutions regular everyw
here and at the origin in particular. These are then solitons or regular b
lack holes. We will comment on the generality of the solutions at hand and
several other properties.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ruben Manvelyan (Yerevan Physics Institute)
DTSTART:20240313T100000Z
DTEND:20240313T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/7
DESCRIPTION:Title: On Correlation Functions for Conformal Higher Spin Currents in d dimen
sion\nby Ruben Manvelyan (Yerevan Physics Institute) as part of AUTH H
EP-TH Seminars\n\nLecture held in Theory Seminar Room (4th Floor).\n\nAbst
ract\nWe revisit the problem of classification and explicit construction o
f the conformal three-point correlation functions of currents of arbitrary
integer spin in arbitrary dimensions.\nFor the conserved currents\, we se
t up the equations for the conservation conditions and solve them complete
ly for some values of spins\, confirming the earlier counting of the numbe
r of independent structures matching them with the higher-spin cubic verti
ces in one higher dimension. We discuss the general solution for the corre
lators of conserved currents and delegate to a follow-up work.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theodoros Horikis (University of Ioannina)
DTSTART:20240410T090000Z
DTEND:20240410T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/8
DESCRIPTION:Title: Dark soliton propagation under perturbations\nby Theodoros Horikis
(University of Ioannina) as part of AUTH HEP-TH Seminars\n\nLecture held
in Theory Seminar Room (4th Floor).\n\nAbstract\nDark solitons of the defo
cusing nonlinear Schrodinger (NLS) equation will be considered. After a sh
ort introduction to the main concepts\, we will present a direct perturbat
ion method for approximating dark solitons of the NLS equation under the i
nfluence of perturbations. It is found that these solitons under the influ
ence of perturbations develop a shelf that propagates with speed determine
d by the background intensity. The dynamical properties of the soliton and
the shelf are obtained from integral relations arising from the conservat
ion laws of the NLS equation. To reveal the importance of these shelves\,
we study the generation and dynamics of dark solitons in various systems\,
and make possible connections of the perturbed NLS with other important e
quations that exhibit shelves.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Xavier Bekaert (University of Tours)
DTSTART:20240605T090000Z
DTEND:20240605T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/9
DESCRIPTION:Title: Holographic realisation of Carrollian conformal scalars\nby Xavier
Bekaert (University of Tours) as part of AUTH HEP-TH Seminars\n\n\nAbstra
ct\nThe singleton is a remarkable unitary representation of the conformal
algebra\, which was first investigated by Dirac in the sixties\, and whose
bulk/boundary description in the seventies by Flato and Fronsdal is somet
imes considered as a precursor of the AdS/CFT correspondence. The flat lim
it of the singleton on AdS spacetime is shown to provide the bulk dual\, i
n Minkowski spacetime\, of the Carrollian conformal scalar field living at
null infinity.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anatoly Dymarsky (University of Kentucky)
DTSTART:20240529T140000Z
DTEND:20240529T150000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/10
DESCRIPTION:Title: Krylov complexity and chaos\nby Anatoly Dymarsky (University of K
entucky) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nI will review rece
nt attempts to understand if dynamics in Krylov space (including Krylov co
mplexity) is a proper probe of quantum chaos. The talk will include a numb
er of new results evaluating asymptotic value of Krylov complexity and\, t
ime permitting\, discuss temperature dependence of physics in Krylov space
.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alessandro Georgoudis (Queen Mary University of London)
DTSTART:20240522T090000Z
DTEND:20240522T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/11
DESCRIPTION:Title: The O(N) Monolith reloaded: Sum rules and Form Factor Bootstrap\n
by Alessandro Georgoudis (Queen Mary University of London) as part of AUTH
HEP-TH Seminars\n\n\nAbstract\nIn this talk I will present the S-matrix b
ootstrap program and its application to the study of 2d gapped and UV comp
lete QFTs. In our work we extend the known results from pure S-matrix boot
strap by including into the set-up form factors and spectral functions of
the stress energy tensor and conserved currents. I will explain how this e
xtended set-up works and show how the associated sum rules allows us to pu
t bounds on quantities like the central charge of the underlying conformal
theories in the UV. In this context I will show how from our results a bi
g portion of the boundary of the space of allowed theories can only flow f
rom CFTs with infinite central charges. I will track this result down to a
particular behaviour of the amplitudes in physical kinematics and discuss
its physical implications. Based on arxiv:hep-th/2311.03031 in collaborat
ion with L. Córdova\, M. Correia and A. Vuignier.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Georgios Karananas (Ludwig-Maximilians-Universität München)
DTSTART:20241106T100000Z
DTEND:20241106T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/13
DESCRIPTION:Title: The particle content of (scalar-curvature)^2 gravities\nby Georgi
os Karananas (Ludwig-Maximilians-Universität München) as part of AUTH HE
P-TH Seminars\n\n\nAbstract\nI will show that studying the spectrum of (sc
alar-curvature)^2 gravities on Minkowski background inevitably results int
o a Catch-22: any consistent interpretation of the particle dynamics dicta
tes that no accidental gauge symmetries emerge\, a requirement that cannot
be fulfilled on Minkowski. Such emergent symmetries are artifacts of the
linearized approximation on top of flat background\, suggesting that the a
nalysis of the spectrum on flat background is hindered by strong coupling
effects. Such undesirable symmetries are absent already at the leading non
trivial order in perturbations on non-flat backgrounds\, e.g. de Sitter sp
acetime\, which are the appropriate ones for studying the particle dynamic
s of R^2 gravities.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sven F. Stawinski (Universität Bonn)
DTSTART:20240925T090000Z
DTEND:20240925T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/14
DESCRIPTION:Title: Recursive Structure of Conformal Four-Point Integrals\nby Sven F.
Stawinski (Universität Bonn) as part of AUTH HEP-TH Seminars\n\n\nAbstra
ct\nWe consider conformal four-point integrals to investigate how much of
their mathematical structure in two spacetime dimensions carries over to h
igher dimensions. In particular\, we discuss recursions in the loop order
and spacetime dimension. This results e.g. in new expressions for conforma
l ladder integrals with generic propagator powers in all even dimensions a
nd allows us to lift results on 2d fishnet integrals with underlying Calab
i-Yau geometry to higher dimensions. Moreover\, we demonstrate that the Ba
sso-Dixon generalizations of these integrals obey different variants of th
e Toda equations of motion\, thus establishing a connection to classical i
ntegrability and the family of so-called tau-functions. We then show that
all of these integrals can be written in a double copy form that combines
holomorphic and anti-holomorphic building blocks. Here integrals in higher
dimensions are constructed from an intersection pairing of two-dimensiona
l "periods'' together with their derivatives.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pierre Vanhove (Université Paris-Saclay)
DTSTART:20250129T100000Z
DTEND:20250129T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/15
DESCRIPTION:Title: From scattering amplitudes to gravitational waves observables\nby
Pierre Vanhove (Université Paris-Saclay) as part of AUTH HEP-TH Seminars
\n\n\nAbstract\nThe necessity for high precision analytic computations of
gravitational waves emitted from the gravitational two-body scattering in
Einstein gravity has driven the development of scattering amplitudes techn
iques for classical gravitational observables. This approach has yielded a
nalytic results that are in impressive agreement with those obtained from
numerical general relativity.\n\nIn this presentation\, we will elucidate
the noteworthy correlation between the perturbative quantum scattering met
hodology and the classical post-Minkowskian expansion. This framework offe
rs a coherent framework for comprehending gravitational radiation. Additio
nally\, it provides a natural embedding of Einstein gravity into an effect
ive field theory framework.\n\nWe will present a novel cubic formulation o
f gravity and demonstrate how this facilitates the computation of gravitat
ional observables to all orders in perturbation.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elli Pomoni (DESY\, Hamburg)
DTSTART:20250305T100000Z
DTEND:20250305T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/16
DESCRIPTION:Title: Exploring thermal CFTs\nby Elli Pomoni (DESY\, Hamburg) as part o
f AUTH HEP-TH Seminars\n\n\nAbstract\nIn this talk\, I will present recent
developments in the study of Conformal Field Theories (CFTs) at finite te
mperature. The motivation of this work is different applications to hologr
aphy\, black holes in AdS as well as interesting statistical physics syste
ms. After a short overview to the usual (zero Temperature) conformal boots
trap approach to CFTs\, I will discuss how the dynamics at finite temperat
ure are constrained by the Kubo-Martin-Schwinger (KMS) condition. I will p
resent explicit sum rules for one-point functions\, providing a basis for
setting up a numerical bootstrap problem\, the power of which I will demon
strate with specific examples. Furthermore\, the KMS condition can be used
to extract the leading behavior of one-point functions for heavy operator
s analytically. Lastly\, I will show how to generalize this framework to t
emporal line-defects akin to Polyakov loops in gauge theories.\n\nThe talk
will be based on 2306.12417\, 2312.13030\, 2407.14600 and 2411.00978\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mohsen Alishahiha (IPM\, Tehran)
DTSTART:20250219T100000Z
DTEND:20250219T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/17
DESCRIPTION:Title: Quantum chaos and Krylov complexity\nby Mohsen Alishahiha (IPM\,
Tehran) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nWe demonstrate\,\nt
hrough analytical computations\, that in finite many-body systems\, while
ramp and plateau are\ntwo generic features of Krylov complexity\, the mann
er in which complexity saturates reveals the\nchaotic nature of the system
. In particular\, we show that the dynamics towards saturation precisely\n
distinguish between chaotic and integrable systems.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthieu Vilatte (University of Mons)
DTSTART:20250123T130000Z
DTEND:20250123T160000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/18
DESCRIPTION:Title: Asymptotically flat gravity and the emergence of Carrollian physics\nby Matthieu Vilatte (University of Mons) as part of AUTH HEP-TH Semina
rs\n\nLecture held in Theory Seminar Room (4th Floor).\n\nAbstract\nIn thi
s lecture we will study gravity in spacetimes that go back to Minkowski at
infinity i.e. asymptotically flat spacetimes. This framework allows to st
udy the gravitationnal field infinitely far away from an isolated source.
Detailing the simple example of Minkoswski itself will reveal the existenc
e of three types of infinities: timelike\, spacelike and null. The last on
e being the locus where gravitationnal radiation can be captured\, we will
spend some time detailing its rigourous construction using the procedure
of conformal compactification à la Penrose. Along the way we will discove
r that symmetries\, namely (conformal) Carrollian symmetries\, are at work
at null infinity. Then\, going in the so-called Bondi coordinates\, we sh
all show the relation between (conformal) Carroll symmetries and the symme
tries near infinity of asymptotically flat spacetimes\, the BMS group. If
time allows\, we will finally explain how one can use these coordinates to
prove the existence of gravitationnal waves in the non-linear regime of g
eneral relativity.\n\nLiterature:\n\n“The seminal papers”\n- A. Ashtek
ar\, Geometry and physics at null infinity\, 1409.1800 [gr-qc]\n\n- H. Bon
di et al’\, Gravitational waves in general relativity. 7. Waves from axi
symmetric isolated systems\, Proc.Roy.Soc.Lond.A 269 (1962) 21-52\n\n- R.K
. Sachs\, Gravitational waves in general relativity. 8. Waves in asymptoti
cally flat space-times\, Proc.Roy.Soc.Lond.A 270 (1962) 103-126\n\n- R. Pe
nrose\, Conformal treatment of infinity\, Gen.Rel.Grav. 43 (2011) 901-922
(reprint)\, originally from 1962\n\n“Modern approaches” \n\n- R. Ruzzi
coni\, Asymptotic symmetries and the gauge fixing approach to the BMS grou
p\, PoS Modave2019 (2020) 003\n\n- A Fiorucci\, Leaky covariant phase spac
es and application to Lambda-BMS symmetry\, PhD Thesis\, Chapter 2.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Niels Obers (Niels Bohr Institute)
DTSTART:20250312T100000Z
DTEND:20250312T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/19
DESCRIPTION:Title: A BPS Road to Holography: Decoupling Limits and Non-Lorentzian Geomet
ries [Cancelled]\nby Niels Obers (Niels Bohr Institute) as part of AUT
H HEP-TH Seminars\n\n\nAbstract\nI explore decoupling limits that lead to
matrix theories on D-branes\, focusing on their BPS nature and the emergen
ce of non-Lorentzian target space geometries. In these limits\, D-branes e
xperience instantaneous gravitational forces\, and when applied to curved
geometries\, it is shown that a single decoupling limit leads to the AdS/C
FT correspondence. By applying two such limits\, we generate new holograph
ic examples\, including those with non-Lorentzian bulk geometries. I also
discuss the relationship between matrix theories and non-relativistic str
ing theory\, and their uplift to M-theory. Finally\, we demonstrate that r
eversing these decoupling limits connects to the TTbar deformation in two
dimensions. This provides a new perspective on the near-horizon brane geom
etry and leads to TTbar-like flow equations for the Dp-brane DBI action.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fedor K. Popov (University of Stony Brook)
DTSTART:20250226T150000Z
DTEND:20250226T160000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/20
DESCRIPTION:Title: Temperature-Resistent Order in 2+1 dimensions\nby Fedor K. Popov
(University of Stony Brook) as part of AUTH HEP-TH Seminars\n\n\nAbstract\
nHigh temperatures are typically thought to increase disorder. Here we exa
mine this idea in Quantum Field Theory in 2+1 dimensions. For this sake we
explore a novel class of tractable models\, consisting of nearly-mean-fie
ld scalars interacting with critical scalars. We identify UV-complete\, lo
cal\, unitary models in this class and show that symmetry breaking Z2
→∅ occurs at any temperature in some regions of the phase diagram. Th
is phenomenon\, previously observed in models with fractional dimensions\,
or in the strict planar limits\, or with non-local interactions\, is now
exhibited in a local\, unitary 2+1 dimensional model with a finite number
of fields.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Justin R. David\, (Indian Institute of Science\, Bangalore)
DTSTART:20250212T090000Z
DTEND:20250212T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/21
DESCRIPTION:Title: The large N vector model on a sphere and at finite temperature\n
by Justin R. David\, (Indian Institute of Science\, Bangalore) as part of
AUTH HEP-TH Seminars\n\n\nAbstract\nThe $O(N)$ vector model with a quarti
c interaction in 3 dimensions \n is an one of the most well studied quan
tum field theories. It is important to describe strongly correlated physi
cs and its non-trivial fixed point at large $N$ serves as the holographic
dual to Vasiliev's higher spin theory on $AdS_3$. In spite of the extens
ive studies\, there is no systematic study of the model on $S^1\\times S^2
$. We develop a method to evaluate the partition function and energy dens
ity of a massive scalar on a 2-sphere of radius $r$ and at finite temperat
ure $\\beta$ as power series in $\\beta/r$. Each term in the power series
can be written in terms of polylogarithms. We use this result to obtain th
e gap equation for the large $N$\, critical O(N) in the large radius exp
ansion.\nSolving the gap equation perturbatively we obtain the leading fin
ite size corrections to thermal one point functions in the model. \nThis i
ncludes one point functions of the higher spin\, $s>2$ currents of the \n
model for which we use the Euclidean inversion formula. \nThe talk will be
gin with a brief introduction to the relevance of finite temperature \nphy
sics in holography.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chris Hull (Imperial College\, London)
DTSTART:20250409T090000Z
DTEND:20250409T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/23
DESCRIPTION:Title: Monopoles\, Dirac Strings and Generalised Symmetries\nby Chris Hu
ll (Imperial College\, London) as part of AUTH HEP-TH Seminars\n\n\nAbstra
ct\nDirac’s quantum theory of magnetic monopoles requires a Dirac strin
g attached to each monopole\, and it is important that the fields equation
s do not depend on the positions of the Dirac strings\, provided that they
comply with the Dirac veto: they must not intersect the worldliness of el
ectrically charged particles. This theory is revisited and it is shown tha
t it has generalised symmetries related to the freedom of moving the Dirac
strings. The Dirac veto is interpreted as an anomaly and \nthe possibilit
y of cancelling the anomaly by embedding in a higher-dimensional theory wi
ll be discussed.\n\nThis talk is based on arXiv:2411.18741\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Manthos Karydas (LBL\, Berkeley)
DTSTART:20250402T090000Z
DTEND:20250402T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/24
DESCRIPTION:Title: On the quantum mechanics of entropic forces\nby Manthos Karydas (
LBL\, Berkeley) as part of AUTH HEP-TH Seminars\n\nLecture held in Theory
Seminar Room (4th Floor).\n\nAbstract\nIt has been conjectured that the gr
avitational interaction may arise as an entropic force rather than as a re
sult of virtual quanta exchange of a fundamental field. In this talk I wil
l present a set of microscopic quantum models which realize this idea in d
etail. I will describe a simple mechanism by which Newton’s law of gravi
ty arises from the extremization of the free energy of a collection of qub
its. I will show both a local and non-local model version of the construct
ion and discuss how to distinguish these entropic models from ordinary per
turbative quantum gravity using existing observations and near term experi
ments. Based on 2502.17575 with Daniel Carney\, Thilo Scharnhorst\, Roshni
Singh and Jacob M. Taylor.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marco Meineri (University of Turino)
DTSTART:20250430T090000Z
DTEND:20250430T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/25
DESCRIPTION:Title: No-go theorems for higher-spin charges in AdS_2\nby Marco Meineri
(University of Turino) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nHig
her-spin conserved currents and charges feature prominently in integrable
2d QFTs in flat space. Motivated by the question of integrable field theor
ies in Anti de-Sitter space\, we consider the consequences of higher-spin
currents for QFTs in AdS2\, and find that their effect is much more constr
aining than in flat space. Specifically\, it is impossible to preserve: (a
) any higher-spin charges when deforming a massive free field by interacti
ons\, or (b) any spin-4 charges when deforming a CFT by a Virasoro primary
. Along the way\, we explain how higher-spin charges lead to integer spaci
ng in the spectrum of primaries and to constraints on correlation function
s. We also comment on consequences for critical long-range statistical mod
els.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Niels Obers (Niels Bohr Institute)
DTSTART:20250514T090000Z
DTEND:20250514T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/26
DESCRIPTION:Title: A BPS Road to Holography: Decoupling Limits and Non-Lorentzian Geomet
ries\nby Niels Obers (Niels Bohr Institute) as part of AUTH HEP-TH Sem
inars\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Achilleas Porfyriadis (University of Crete)
DTSTART:20250611T090000Z
DTEND:20250611T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/27
DESCRIPTION:Title: Accidental symmetries near extreme black hole horizons\nby Achill
eas Porfyriadis (University of Crete) as part of AUTH HEP-TH Seminars\n\nL
ecture held in Theory Seminar Room (4th Floor).\n\nAbstract\nNear the hori
zon of extremal black holes the linear Einstein equations acquire an accid
ental symmetry. This symmetry is a linearized diffeomorphism which acts on
the perturbative solutions around the background near-horizon spacetime a
nd maps them amongst themselves. It is accidental in the sense that it enl
arges the set of such transformations to make it strictly larger than the
background's isometries. Accidental symmetries combine neatly with the nea
r-horizon SL(2) isometries inside a Virasoro algebra and can be thought of
as on-shell large diffeomorphisms/asymptotic symmetries of AdS2.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pantelis Panopoulos (APCTP\, Pohang)
DTSTART:20250604T090000Z
DTEND:20250604T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/28
DESCRIPTION:Title: Wess Zumino action and Casimir energy of N=1 Superconformal Field The
ories\nby Pantelis Panopoulos (APCTP\, Pohang) as part of AUTH HEP-TH
Seminars\n\n\nAbstract\nIn this talk I will start with an introduction to
anomalies using the unified framework of gauged symmetries. Next I will
be focusing on Superconformal anomalies as an application. In the main cor
e of the talk I will first define the Casimir energy of Superconformal Fie
ld Theories (SCFTs) through the supersymmetry algebra and how it receives
contributions from anomalies. Next by giving a general introduction to Wes
s-Zumino (WZ) anomaly action\, some simple examples of growing complicatio
n will be presented\, concluding with the WZ-action of N=1 SCFTs as our m
ain aim. Discrepancy of our Casimir energy with the rest of bibliography\,
its relation to the Wess-Zumino action evaluated at different schemes a
nd how WZ-action contributes towards the resolution of this mismatch wil
l be emphasized.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Maurizzio Firrotta (University of Crete)
DTSTART:20250826T090000Z
DTEND:20250826T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/29
DESCRIPTION:Title: The light after the string: Absorption and Emission from HES states\nby Maurizzio Firrotta (University of Crete) as part of AUTH HEP-TH Sem
inars\n\nLecture held in Theory Seminar Room (4th Floor).\n\nAbstract\nI w
ill present a recent extension of the Veneziano and Shapiro-Virasoro ampli
tudes to the case of arbitrarily excited strings (AES) in critical bosonic
string theory. I will also discuss several novel applications\, such as t
he absorption universality emerging from the absorption cross section of A
ES and the emission rate of AES with particular focus on the photon and gr
aviton emission spectrum. Finally I will comment on the spin multipole exp
ansion and the classical infinite spin limit of three-point Heavy-Light-He
avy string amplitudes where the heavy states belong to both leading and su
b-leading Regge trajectories.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sokratis Trifinopoulos (CERN)
DTSTART:20251022T090000Z
DTEND:20251022T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/30
DESCRIPTION:Title: Properties of Fundamental Particles from Quantum Information?\nby
Sokratis Trifinopoulos (CERN) as part of AUTH HEP-TH Seminars\n\nLecture
held in Meeting room of the Department of Physics (4th floor\, room 26).\n
\nAbstract\nScattering processes provide a natural arena to explore how qu
antum information concepts manifest in particle physics. Beginning with lo
w-energy nucleon–nucleon scattering\, I show how characteristic entangle
ment patterns are tied to emergent symmetries\n such as the Wigner SU(4) s
ymmetry. Turning to gauge and gravitational interactions\, gluon and gravi
ton scattering (and their supersymmetric counterparts) exhibit maximal ent
anglement at perpendicular kinematics\, while magic remains below its maxi
mal theoretical\n value. However\, it is noteworthy that there exist an an
ticorrelation between magic production and the spin of the participating p
articles. Finally\, a surprising link emerges when studying entanglement i
n electroweak 2→2 processes at π/2 scattering angles:\n the amount of e
ntanglement is minimized when the Cabibbo–Kobayashi–Maskawa (CKM) matr
ix is nearly (but not exactly) diagonal\, in qualitative agreement with ob
servation. Extending this reasoning to the lepton sector\, the same princi
ple favors a Pontecorvo–Maki–Nakagawa–Sakata\n (PMNS) matrix with tw
o large angles and a smaller one\, again consistent with data\, together w
ith a possible indication of suppressed CP violation. These recurring patt
erns suggest that information-theoretic measures may provide a new perspec
tive on the structure\n of fundamental interactions.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Enrico Marchetto (DESY)
DTSTART:20251126T100000Z
DTEND:20251126T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/31
DESCRIPTION:Title: Analytic tools for thermal holographic correlators (and not only)
\nby Enrico Marchetto (DESY) as part of AUTH HEP-TH Seminars\n\n\nAbstract
\nFinite-temperature systems have always played a central role in physics.
In recent years\, the study of conformal field theories in a thermal stat
e has gained momentum\, with applications ranging from condensed matter to
black holes through the AdS/CFT correspondence. In this talk\, I will int
roduce a general analytic bootstrap framework for thermal two-point functi
ons\, explaining how to decompose them in terms of generalized free field
correlators. I will then apply this framework to holographic CFTs at leadi
ng order in large N\, focusing in particular on thermal scalar two-point f
unctions. I will address the specific challenges arising from considering
scalars with integer dimensions\, and I will show how these tools are able
to produce a prediction that is not only consistent with previous studies
of scalars with half-integer dimensions\, but also in agreement with the
numerical solution of the wavefunction in the bulk.\n\nThis talk is based
on the works hep-th/2506.06422 and hep-th/2510.20894.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luca Ciambelli (Perimeter Institute)
DTSTART:20251030T150000Z
DTEND:20251030T160000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/32
DESCRIPTION:Title: Radiation\, Holography\, and Quantum Null Physics\nby Luca Ciambe
lli (Perimeter Institute) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nT
his seminar is divided into two parts. The first explores gravitational ra
diation in spacetimes with a cosmological constant. For negative values\,
we relate it to the fluid/gravity correspondence and to dissipative proces
ses in the dual boundary fluid. By then taking the flat limit using classi
c techniques developed together with the Thessaloniki group\, we show how
specific aspects of Carrollian boundary physics are sourced by bulk radiat
ion\, providing a first step toward understanding dissipative phenomena in
Carrollian frameworks.\n\nThe second part\, connected to the first throug
h the physics of null hypersurfaces\, turns to quantum physics and the rec
ently developed framework of quantum null geometry. I will describe the ca
nonical quantization of gravity on null hypersurfaces\, offering a potenti
al resolution to the problem of time in QG. Finally\, I will connect this
to recent bottom-up approaches to defining the entropy of generic subregio
ns in QG and to the study of quantum area fluctuations. This involves the
use of geometric modular flows to implement the crossed-product constructi
on in semiclassical gravity\, the generalization of entanglement wedges be
yond AdS/CFT\, and connections to QG tabletop experiments probing quantum
fluctuations of the area of a causal diamond.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Adrien Fiorucci (Ecole Polytechnique)
DTSTART:20251015T090000Z
DTEND:20251015T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/33
DESCRIPTION:Title: Holographic Derivation of BMS Flux-Balance Laws\nby Adrien Fioruc
ci (Ecole Polytechnique) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nTh
e main challenges in formulating a holographic correspondence for asymp-\n
totically flat spacetimes stem from the null nature of the conformal bound
ary\nand the non-conservation of gravitational charges in the presence of
bulk ra-\ndiation. In this talk\, I will present the systematic and mathem
atically robust\napproach to understanding and deriving the associated flu
x-balance laws\nfrom geometric principles defined intrinsically at the bou
ndary.\n\nI will begin by reviewing key aspects of the geometry at null in
finity\, known\nas conformal Carroll geometry. I will highlight that the b
oundary affine con-\nnections contain degrees of freedom that naturally ac
t as sources encoding\nradiation in a holographic framework. I will then d
erive flux-balance laws\nfor an effective field theory formulated at the b
oundary\, using novel tech-\nniques that introduce “hypermomenta” as t
he responses to fluctuations in\nthe boundary connection. These equations
reproduce the celebrated BMS\nflux-balance laws in a convenient boundary g
auge.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Romain Ruzziconi (Harvard University)
DTSTART:20251119T170000Z
DTEND:20251119T180000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/34
DESCRIPTION:Title: Flat Space/Carrollian Limit of AdS/CFT\nby Romain Ruzziconi (Harv
ard University) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nCarrollian
holography provides a framework for flat space holography\, proposing that
gravity in four-dimensional asymptotically flat spacetime is dual to a Ca
rrollian CFT in three dimensions living at null infinity. In this talk\, I
will present this framework and explain how massless scattering amplitude
s in flat space can be re-expressed as Carrollian CFT correlators at the b
oundary\, referred to as Carrollian amplitudes. I will then show that thes
e correlators naturally arise from the Carrollian limit of holographic CFT
correlators computed via AdS Witten diagrams\, establishing a corresponde
nce between the flat space limit in the bulk and the Carrollian limit at t
he boundary. This paves the way towards deriving flat space holography fro
m the flat space/Carrollian limit of the AdS/CFT correspondence.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gerben Oling (University of Edinburgh)
DTSTART:20260121T090000Z
DTEND:20260121T100000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/35
DESCRIPTION:Title: A boundary energy-momentum tensor from gravity near null infinity
\nby Gerben Oling (University of Edinburgh) as part of AUTH HEP-TH Seminar
s\n\n\nAbstract\nI will discuss how solving the Einstein equations in a ra
dial expansion around null infinity in terms of arbitrary boundary metric
data can be used to derive a boundary energy-momentum tensor whose diffeom
orphism Ward identities generalize the usual Bondi loss equations. General
izing holography from AdS/CFT to spacetimes with vanishing cosmological co
nstant has been a long-standing goal. The limit of vanishing AdS curvature
radius can be interpreted as an ultra-local or Carrollian limit on the bo
undary\, which is related to the (conformal) Carrollian structure at null
infinity. However\, a straightforward application of such Carrollian limit
s to standard Lorentzian field theories often gives clearly unsatisfactory
results. Motivated by this\, we can turn to the bulk for hints on how suc
h putative dual Carroll theories should be more appropriately constructed.
In this talk\, I will describe some of the recent work on extracting an e
nergy-momentum-news complex from the dynamics of Einstein gravity near asy
mptotic null infinity in three and four bulk dimensions. In analogy with s
tandard holographic renormalization in AdS/CFT\, this is achieved by radia
lly solving the Einstein equations near null infinity for general boundary
data and introducing appropriate counterterms for the resulting on-shell
action\, and variations then define currents and their corresponding Ward
identities.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimitrios Zoakos (University of Patras)
DTSTART:20251203T100000Z
DTEND:20251203T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/36
DESCRIPTION:Title: Holography and a codimension-2 defect CFT\nby Dimitrios Zoakos (U
niversity of Patras) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nIn thi
s talk I will present a new holographic duality between a non-supersymmetr
ic defect conformal field theory & its gravity dual. On the gravity side\,
the defect is realized by a D5 probe brane that wraps an S^2 subset of th
e S^5 and carries k units of flux through the S^2. The brane ends on an R^
(1\,1) subspace of the AdS5 boundary resulting to a codimension-2 defect.
On the field theory side\, the defect is described by a classical solution
whose precise form we determine. We calculate the one-point functions of
the energy-momentum tensor and of the chiral primary operators\, both at s
trong and at weak coupling and in an appropriate limit we find compelling
agreement between the two results.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vasileios Letsios (University of Mons)
DTSTART:20251210T100000Z
DTEND:20251210T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/37
DESCRIPTION:Title: Features of Gravitini and Supersymmetry on de Sitter spacetime - [Can
celled]\nby Vasileios Letsios (University of Mons) as part of AUTH HEP
-TH Seminars\n\nLecture held in Theory Seminar Room (4th Floor).\n\nAbstra
ct\nIt is commonly believed that a unitary supersymmetric quantum field th
eory (QFT) involving graviton and gravitino fields on fixed 4-dimensional
de Sitter spacetime (dS4) cannot exist due to known challenges associated
with supersymmetry (SUSY) on spaces with positive cosmological constant. I
n this talk\, we contradict this expectation by presenting a new unitary s
upersymmetric QFT on dS4 background: the free supersymmetric theory of th
e chiral graviton and chiral gravitino fields. The theory overcomes the kn
own obstacles to unitary global SUSY on de Sitter because the commutator b
etween two SUSY transformations closes on the conformal algebra so(4\,2)
rather than the de Sitter algebra so(4\,1). Crucially\, the \nso(4\,2) sy
mmetry is realised through unconventional conformal-like transformations.
Along the way\, we will discuss curious features of the free gravitino QF
T on dS4: canonical quantisation with the use of a real action functional
forces the field to be chiral\, if one insists on the positivity of the n
orm in the QFT Fock space. As a complementary approach\, we will compute t
he Euclidean 1-loop path integral of the gravitino on Euclidean dS4\, an
d show that group-theoretic characters associated with the UIRs of so(4\,1
) appear. This indicates that the tension between chirality and unitarity
seems to be absent in the Euclidean picture.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sašo Grozdanov (University of Edinburgh)
DTSTART:20260218T100000Z
DTEND:20260218T110000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/39
DESCRIPTION:Title: Spectra of black hole perturbations and the spectral duality relation
\nby Sašo Grozdanov (University of Edinburgh) as part of AUTH HEP-TH
Seminars\n\n\nAbstract\nPerturbations of black holes generate fluctuations
in spacetime known as gravitational waves. In an (approximately) asymptot
ically flat universe\, the spectra of damped gravitational waves (the quas
inormal modes) in the two channels of black hole perturbations (longitudin
al and transverse) are related by the so-called isospectrality property. I
n this talk\, I will present a new universal spectral duality relation tha
t connects the quasinormal mode spectra in spacetimes with a negative cosm
ological constant. Through the AdS/CFT correspondence\, this gravitational
relation implies a series of nontrivial constraints on the spectra of QFT
s exhibiting S-duality (or particle–vortex duality)\, as well as on conf
ormal field theories with double-trace deformations. As part of my talk\,
I will also discuss a few other properties of such thermal QFT spectra\, a
nd how their analytic reconstruction can be understood\, within the langua
ge of the AdS/CFT correspondence\, through the phenomenon of pole-skipping
.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sahand Seifnashri (Institute of Advanced Studies)
DTSTART:20260128T140000Z
DTEND:20260128T150000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/40
DESCRIPTION:Title: Exactly Solvable 1+1d Chiral Lattice Gauge Theories\nby Sahand Se
ifnashri (Institute of Advanced Studies) as part of AUTH HEP-TH Seminars\n
\n\nAbstract\nUsing the modified Villain lattice Hamiltonian formulation o
f the 1+1d compact boson theory\, we construct exactly solvable abelian ch
iral lattice gauge theories in two spacetime dimensions. As a concrete exa
mple\, we derive an explicit quadratic lattice Hamiltonian for the "34-50"
chiral gauge theory. We further show that N copies of the modified Villai
n theory realize the full T-duality transformations\, which we then use to
solve and analyze these lattice gauge theories.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Themistocles Zikopoulos (Perimeter Institute)
DTSTART:20260108T113000Z
DTEND:20260108T123000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/41
DESCRIPTION:Title: Conformal boundaries in gravity\nby Themistocles Zikopoulos (Peri
meter Institute) as part of AUTH HEP-TH Seminars\n\nLecture held in Theory
Seminar Room (4th Floor).\n\nAbstract\nWe discuss aspects of black holes\
, confined within a timeline boundary endowed with conformal boundary cond
itions — whereby the conformal class of the boundary metric is held fixe
d. In Euclidean signature\, the gravitational action of such solutions pre
cisely coincides with the thermal effective action of a conformal field th
eory in one less dimension\, for all values of the cosmological constant.
In Lorentzian signature\, the Weyl factor of the boundary metric exhibits
rich dynamics. Our discussion concerns general Lovelock gravity theories i
n arbitrary dimension. Based on joint work with D. Galante and R. Myers.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simone Giombi (Princeton University)
DTSTART:20260311T150000Z
DTEND:20260311T160000Z
DTSTAMP:20260315T022429Z
UID:AUTH-HEP-TH/42
DESCRIPTION:Title: Loops in AdS and the Wilson-Fisher BCFT\nby Simone Giombi (Prince
ton University) as part of AUTH HEP-TH Seminars\n\n\nAbstract\nA conformal
field theory in the presence of a boundary (BCFT) can be mapped by a conf
ormal transformation to the equivalent problem of studying the CFT in anti
de Sitter (AdS) space. I will use this approach to analyze the Wilson-Fis
her fixed point of the O(N) model with a boundary. In particular\, I will
discuss the calculation of the free energy of the CFT in AdS space using t
he epsilon expansion\, and use it to extract predictions for the boundary
central charge and other observables of the BCFT in three dimensions.\n
LOCATION:https://researchseminars.org/talk/AUTH-HEP-TH/42/
END:VEVENT
END:VCALENDAR