BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:David Osten (Ludwig Maximilian University/Max-Planck-Institute for Physics\, Munich) DTSTART:20200624T150000Z DTEND:20200624T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/1 DESCRIPTION:Title: Current Algebra and Generalised Geometry\nby David Osten (L udwig Maximilian 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 str ing theory. Generalised geometry is a generalisation of Riemannian geometr y that captures certain 'non-geometric' backgrounds which are nevertheless well-defined in string theory. A convenient characterisation of such back grounds is given in terms of the so-called generalised fluxes.\n\nIn the s econd part of the talk I want to discuss the meaning of these generalised fluxes in the worldsheet theory. There\, they describe a deformation of th e canonical Poisson structure -- namely the current algebra. Besides appli cations to magnetic backgrounds and integrable sigma models which motivate d 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 inte rpretations of the generalised flux backgrounds\, to generalisations of T- duality and to generalisations to M-theory.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Frederic Bruenner (Vienna University of Technology (TU Wien)) DTSTART:20200708T150000Z DTEND:20200708T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/2 DESCRIPTION:Title: Gauge/gravity duality and the phenomenology of hadrons\nby Frederic Bruenner (Vienna University of Technology (TU Wien)) as part of T heoretical and Mathematical Physics\n\n\nAbstract\nI will give a pedagogic al introduction to aspects of hadronic physics at low energy\, and show ho w the methodology of gauge/gravity duality may be applied to certain probl ems arising 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 hadr ons we observe in collider experiments\, in part due to the lack of theore tical predictions of their decay rates. I will show how gauge/gravity dual ity can be used to calculate glueball decay rates\, and discuss potential implications.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Jose Alejandro Rosabal (Asia Pacific Center for Theoretical Physic s\, Pohang) DTSTART:20200722T110000Z DTEND:20200722T130000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/3 DESCRIPTION:Title: Schwarzschild black hole thermodynamic entropy on a nice slice< /a>\nby Jose Alejandro Rosabal (Asia Pacific Center for Theoretical Physic s\, Pohang) as part of Theoretical and Mathematical Physics\n\n\nAbstract\ nIn this seminar I will present the calculation of the thermodynamic entro py of a Schwarzschild black hole on a nice slice. This can be seen as a wa rm up to address the calculation of the Von Neumann entropy for two interv als\, that includes a portion of the interior of the black hole\, and the Page curve. In the end I will comment on the relation between this work an d some recent proposal.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Nikita Kolganov (ITMP MSU\, Moscow) DTSTART:20200923T150000Z DTEND:20200923T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/4 DESCRIPTION:Title: Constrained modified gravities: generalized unimodular gravity and beyond\nby Nikita Kolganov (ITMP MSU\, Moscow) as part of Theoreti cal and Mathematical Physics\n\n\nAbstract\nIn my talk\, I will give you a brief introduction into modified gravity theories\, and then I will proce ed to particular modified gravity models\, which I'm interested in. Most o f the modified gravities are equivalent to the General Relativity\, equipp ed with some additional degrees of freedom. In our case these d.o.f. are o btained by the explicit breaking of general covariance by an algebraic con straint on metric coefficients. I'm going to discuss the covariantization issue of such theories\, its duality to well-known k-essence and self-grav itating media models\, and applications to inflationary cosmology.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Gleb Arutyunov (University of Hamburg) DTSTART:20200930T150000Z DTEND:20200930T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/5 DESCRIPTION:Title: Hamiltonian structures of the spin Ruijsenaars-Schneider models \nby Gleb Arutyunov (University of Hamburg) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nTBA\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Ariel Arza (ITMP MSU\, Moscow) DTSTART:20201007T150000Z DTEND:20201007T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/6 DESCRIPTION:Title: Production of massive particles from the decay of a free massle ss field\nby Ariel Arza (ITMP MSU\, Moscow) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nIn this talk we will show\, in a simp le toy model (H=g\\phi\\chi^2)\, how Bose enhancement allows the decay of a massless field into massive particles. It happens due to a parametric re sonance caused by a big energy density of the decaying field. I will show the instability conditions as well as the energy density threshold for the decay to occur. I will also compute the equivalent of the spontaneous dec ay rate.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Andrei Zotov (Steklov Mathematical Institute RAS) DTSTART:20201021T150000Z DTEND:20201021T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/7 DESCRIPTION:Title: On double elliptic integrable system: characteristic determinan t and Manakov triple\nby Andrei Zotov (Steklov Mathematical Institute RAS) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nWe dis cuss double elliptic integrable systems\, where the dependence on the mome nta of particles is elliptic. These models generalize the relativistic Rui jsenaars integrable systems\, which contain trigonometric (exponential) de pendence on momenta. A brief review on underlying dualities and interrelat ions between integrable systems will be given. We explain how to construct a kind of determinant representation for the known conservation laws. Fin ally\, we will see that in the classical case the double elliptic models a re naturally described by the Manakov L-A-B triple instead of the Lax pair \n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Mikhail Khlopunov (ITMP\, Moscow State University) DTSTART:20201028T150000Z DTEND:20201028T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/8 DESCRIPTION:Title: Modification of the radiation definition in odd dimensions\ nby Mikhail Khlopunov (ITMP\, Moscow State University) as part of Theoreti cal and Mathematical Physics\n\n\nAbstract\nIn this seminar\, I will discu ss modification of the radiation definition for the case of odd-dimensiona l space-time. The standard definition of the wave zone fails in odd dimens ions\, due to the violation of the Huygens principle: the signal from an i nstantaneous flash of current reaches an observer after an interval of tim e required for propagation of the signal at the speed of light\, but then the tail is observed endlessly\; while in even-dimensional spaces an insta nt signal ends instantly at the observation point. The reason is that the retarded Green’s functions of the wave equation in odd dimensions has su pport localised not only on the light cone\, but also inside it. I will di scuss the covariant retarded quantities technique and Rohrlich-Teitelboim definition of the wave zone. Using this definition\, the scalar radiation from a point-like charge\, moving along the circular trajectory in three a nd five-dimensional space-times\, will be computed. The obtained results w ill be verified by the calculations of the spectral distributions of the r adiated energy\, which are indifferent to the dimensionality of the space- time. Also\, the contributions of the tails to the radiation will be discu ssed.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Alexander Zhiboedov (CERN) DTSTART:20201111T150000Z DTEND:20201111T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/9 DESCRIPTION:Title: Event shapes\, the light-ray OPE and superconvergence\nby A lexander Zhiboedov (CERN) as part of Theoretical and Mathematical Physics\ n\n\nAbstract\nI will describe recent progress in understanding event shap es in conformal 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 nonperturbative setting poses many theoretical challenges. I will de scribe some of the recently developed tools to perform computations of con formal event shapes and illustrate them using N=4 SYM. Finally\, I will ex plain how via holography some of the basic properties of conformal event s hapes lead to nontrivial sum rules obeyed by possible UV completions of ge neral relativity.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Sandipan Kundu (Johns Hopkins University) DTSTART:20201118T150000Z DTEND:20201118T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/10 DESCRIPTION:Title: Closed strings and weak gravity condition from higher-spin cau sality\nby Sandipan Kundu (Johns Hopkins University) as part of Theore tical and Mathematical Physics\n\n\nAbstract\nI will show that metastable higher spin particles\, free or interacting\, cannot couple to gravity whi le preserving causality unless there exist higher spin states in the gravi tational sector much below the Planck scale. Causality imposes an upper bo und on the mass of the lightest higher spin particle in the gravity sector in terms of quantities in the non-gravitational sector. I will argue that any weakly coupled UV completion of such a theory must have a gravity sec tor containing infinite towers of asymptotically parallel\, equispaced\, a nd linear Regge trajectories. This implies that the gravity sector has a s tringy structure with an upper bound on the string scale. Another conseque nce of this bound is that all metastable higher spin particles in 4d with masses below the string scale must satisfy a weak gravity condition. Moreo ver\, these bounds also have surprising implications for large N QCD coupl ed to gravity.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Tim Adamo (University of Edinburgh) DTSTART:20201125T150000Z DTEND:20201125T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/11 DESCRIPTION:Title: Scattering in chiral strong backgrounds\nby Tim Adamo (Uni versity of Edinburgh) as part of Theoretical and Mathematical Physics\n\n\ nAbstract\nThere are many reasons to be interested in quantum field theory in the presence of strong\, non-perturbative background fields\, but surp risingly little is known in these scenarios\, especially when compared to trivial backgrounds. For instance\, the full semi-classical S-matrices of gauge theory and gravity are known in a trivial background\, but even for simple strong backgrounds the tree-level amplitudes of these theories have not been computed beyond four-external particles. This raises the questio n: are all-multiplicity formulae (and other hallmarks of the study of scat tering amplitudes in recent years) inextricably tied to trivial background s? In this talk\, I will demonstrate that for a broad class of chiral back grounds in four-dimensions\, we can find all-multiplicity expressions for tree-level scattering amplitudes of gauge theory and gravity which are rem arkably simple and clearly un-related to standard background-coupled field theory on space-time.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Konstantin Zarembo (Niels Bohr Institute\, Nordita) DTSTART:20201202T150000Z DTEND:20201202T170000Z DTSTAMP:20260404T111214Z 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. Localiza tion of the path integral in the quiver CFT potentially gives means to tes t this duality rigorously. The strong-coupling solution of the localizatio n matrix model\, which I will describe\, is in the remarkable qualitative agreement with the holographic dual\, but is not devoid of puzzling featur es.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Fedor Popov (Princeton University) DTSTART:20201209T150000Z DTEND:20201209T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/13 DESCRIPTION:Title: RG Limit Cycles and "Spooky" Fixed Points in Perturbative QFT< /a>\nby Fedor Popov (Princeton University) as part of Theoretical and Math ematical Physics\n\n\nAbstract\nWe study quantum field theories with sexti c interactions in \n3−ϵ dimensions\, where the scalar fields ϕab form irreducible representations under the O(N)2 or O(N) global symmetry group. We calculate the beta functions up to four-loop order and find the Renorm alization Group fixed points. In an example of large N equivalence\, the p arent O(N)2 theory and its anti-symmetric projection exhibit identical lar ge N beta functions which possess real fixed points. However\, for project ion to the symmetric traceless representation of O(N)\, the large N equiva lence is violated by the appearance of an additional double-trace operator not inherited from the parent theory. Among the large N fixed points of t his daughter theory we find complex CFTs. The symmetric traceless O(N) mod el also exhibits very interesting phenomena when it is analytically contin ued to small non-integer values of N. Here we find unconventional fixed po ints\, which we call "spooky." They are located at real values of the coup ling constants gi\, but two eigenvalues of the Jacobian matrix ∂βi/∂g j are complex. When these complex conjugate eigenvalues cross the imaginar y axis\, a Hopf bifurcation occurs\, giving rise to RG limit cycles. This crossing occurs for Ncrit≈4.475\, and for a small range of N above this value we find RG flows which lead to limit cycles.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Ivo Sachs (Ludwig Maximilian University of Munich) DTSTART:20201216T150000Z DTEND:20201216T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/14 DESCRIPTION:Title: Loops in Holography\nby Ivo Sachs (Ludwig Maximilian Unive rsity of Munich) as part of Theoretical and Mathematical Physics\n\n\nAbst ract\nA quantum field theory (QFT) in an (Anti-)de Sitter\, (A-)dS space-t ime 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 reflect ed in CFT\, both in AdS and dS. The latter has a remote connection to dens ity perturbations in the Universe.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Domenico Orlando (INFN Turin\, University of Bern) DTSTART:20210127T150000Z DTEND:20210127T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/15 DESCRIPTION:Title: The O(N) vector model at large charge: EFT\, large N and resur gence\nby Domenico Orlando (INFN Turin\, University of Bern) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nI will discuss the IR fixed point of the O(N) vector model in 3 dimensions (Wilson-Fisher poi nt) 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 d ouble scaling limit of large N\, large charge and finally discuss the use of resurgence to extend the validity of the EFT to sectors of small charge .\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Piotr Tourkine (Paris LPTHE\, CERN) DTSTART:20210203T150000Z DTEND:20210203T170000Z DTSTAMP:20260404T111214Z 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\nAbstra ct\nIn this seminar\, I will talk about recent results about a numerical m ethod to find unitary S-matrices. The method\, based on works of Atkinson\ , was invented in the late 60s and was used as a proof of existence of fun ctions 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 t hose methods for S-matrices in two dimensions\, using two different iterat ive schemes: a fixed-point iteration and Newton's method. Those schemes it erate the unitarity and dispersion relations\, and converge to solutions t o the S-matrix axioms. This numerical strategy provides a solution to the problem of reconstructing the scattering amplitude starting from a given p article production probability. \nAfter a general introduction\, the talk will be focused on how we implemented the algorithms\, what they converge to\, and the conditions under which they converge. We will see that the qu estion of convergence naturally connects to the recent study of the coupli ng maximization 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 dir ections.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Xinan Zhou (Princeton University) DTSTART:20210217T150000Z DTEND:20210217T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/17 DESCRIPTION:Title: Holographic correlators and emergent Parisi-Sourlas supersymme try\nby Xinan Zhou (Princeton University) as part of Theoretical and M athematical Physics\n\n\nAbstract\nIn this talk\, I will first review the recent progress in computing holographic four-point correlators in maximal ly supersymmetric CFTs. I will introduce the so-called Maximally R-symmetr y Violating (MRV) limit\, in which the Mellin amplitudes drastically simpl ify and become easy to compute. From the MRV limit\, I will show that the full amplitudes can be reconstructed by using symmetries. This gives a com plete answer to all tree-level four-point functions in all three maximally supersymmetric backgrounds AdS4xS7\, AdS5xS5\, and AdS7xS4. In the second part of my talk\, I will point out that these results have surprising pro perties. The Mellin amplitudes exhibit an emergent dimensional reduction s tructure\, which allows them to be expressed in terms of only scalar excha nge amplitudes from lower dimensional spacetimes. I will explain that this dimensional reduction structure is closely related to a holographic reali zation of the Parisi-Sourlas supersymmetry.\n\nConference id: 923 6907 457 2\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/17/ END:VEVENT BEGIN:VEVENT SUMMARY:Ricardo Monteiro (Queen Mary University of London) DTSTART:20210224T150000Z DTEND:20210224T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/18 DESCRIPTION:Title: Gravity as a double copy of gauge theory\nby Ricardo Monte iro (Queen Mary University of London) as part of Theoretical and Mathemati cal Physics\n\n\nAbstract\nRelations expressing gravity as a "double copy" of gauge theory appeared first in string theory\, and have been used to c ompute scattering amplitudes in theories of gravity\, with applications to both theory and phenomenology. I will discuss how the double copy extends to solutions to the equations of motion\, including our best known black hole spacetimes\, and how this story connects to the original story for sc attering amplitudes.\n\nMeeting ID: 928 8340 6261\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/18/ END:VEVENT BEGIN:VEVENT SUMMARY:Linus Wulff (Masaryk University) DTSTART:20210303T150000Z DTEND:20210303T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/19 DESCRIPTION:Title: O(D\,D) and string alpha'-corrections\nby Linus Wulff (Mas aryk University) as part of Theoretical and Mathematical Physics\n\n\nAbst ract\nString theory on a d-dimensional torus features an O(d\,d) symmetry. It has been suggested that the low-energy effective action can be formula ted with a larger O(D\,D) symmetry\, even before putting the theory on a t orus. This approach\, which goes by the name of Double Field Theory (DFT)\ , has proven very useful. I will address the problem of constructing highe r derivative invariants in this formalism. In agreement with the literatur e we find that a quadratic Riemann invariant can be constructed\, which ca n account for the first alpha'-correction to the bosonic and heterotic str ing. However\, we find that no cubic or quartic Riemann invariants can be constructed. 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 8415 0220\nPasscode: 995622\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Radu Roiban (Penn State University) DTSTART:20210310T150000Z DTEND:20210310T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/20 DESCRIPTION:Title: Spinning and spinless two-particle dynamics from gravitational scattering amplitudes\nby Radu Roiban (Penn State University) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nIn the appropriate classical limit\, scattering amplitude-based techniques can yield the cla ssical interaction of massive bodies at fixed order in the post-Minkowskia n expansion.\n\nIn this talk we review a framework for the construction of the two-body Hamiltonian for compact binary systems and illustrate it wit h state of the art results for both spinning and spinless systems. Through out we emphasize structure of gravitational interactions and direct relati ons between scattering amplitudes and observables of two-particle dynamics .\n\nMeeting ID: 933 8672 1535\nPasscode: 122819\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Vladimir Rosenhaus (Institute for Advanced Study\, Princeton) DTSTART:20210317T150000Z DTEND:20210317T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/21 DESCRIPTION:Title: Chaotic scattering with a highly excited string\nby Vladim ir Rosenhaus (Institute for Advanced Study\, Princeton) as part of Theoret ical and Mathematical Physics\n\n\nAbstract\nMotivated by the desire to un derstand chaos in the S-matrix of string theory\, we study tree level scat tering amplitudes involving highly excited strings. While the amplitudes f or scattering of light strings have been a hallmark of string theory sinc e its early days\, scattering of excited strings has been far less studied . Recent results on black hole chaos\, combined with the correspondence pr inciple between black holes and strings\, suggest that the amplitudes hav e a rich structure. We review the procedure by which an excited string is formed by repeatedly scattering photons off of an initial tachyon. We comp ute the scattering amplitude of one arbitrary excited string decaying into two tachyons\, and study its properties for a generic excited string. We find the amplitude is highly erratic as a function of both the precise exc ited string state and of the tachyon scattering angle.\n\nMeeting ID: 936 3872 0664\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/21/ END:VEVENT BEGIN:VEVENT SUMMARY:Paul Heslop (Durham University) DTSTART:20210324T150000Z DTEND:20210324T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/22 DESCRIPTION:Title: Towards the Virasoro-Shapiro Amplitude in AdS5xS5\nby Paul Heslop (Durham University) as part of Theoretical and Mathematical Physic s\n\n\nAbstract\nWe propose a systematic procedure for obtaining all singl e trace 1/2-BPS correlators in N=4 super Yang-Mills corresponding to the f our-point tree-level amplitude for type IIB string theory in AdS5xS5. The underlying idea is to compute generalised contact Witten diagrams coming f rom a 10d effective field theory on AdS5xS5 whose coefficients are fixed b y the flat space Virasoro-Shapiro amplitude up to ambiguities related to c ommutators of the 10d covariant derivatives which require additional infor mation such as localisation. We illustrate this procedure by computing str ingy corrections to the supergravity prediction for all single trace 1/2-B PS correlators up to O(α′7)\, and spell out a general algorithm for ext ending this to any order in α′.\n\nID: 949 0759 4642\nPasscode: 121781\ n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/22/ END:VEVENT BEGIN:VEVENT SUMMARY:Congkao Wen (Queen Mary University of London) DTSTART:20210331T150000Z DTEND:20210331T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/23 DESCRIPTION:Title: Integrated four-point correlators in N=4 SYM\nby Congkao W en (Queen Mary University of London) as part of Theoretical and Mathematic al Physics\n\n\nAbstract\nIn this talk\, we will discuss integrated correl ators of four superconformal primaries in N=4 super Yang-Mills\, that are defined by integrating over spacetime coordinates of the four-point correl ator with certain integration measures. The integrated correlators can be computed using supersymmetric localisation\, which are expressed as N-dime nsional matrix-model integrals. We will mostly focus on one of the integra ted correlators. We find that this integrated correlator can be presented as a lattice sum\, which makes manifest the SL(2\, Z) modular invariance o f N=4 SYM. Furthermore\, the integrated correlator obeys a remarkable Lap lace-difference equation\, which relates the correlator of SU(N) theory wi th those of SU(N-1) and SU(N+1) theories. The expression allows us to obta in exact results of the integrated correlator in various limits. For insta nce\, in perturbation\, the expression is checked to be consistent with kn own results in the literature\; in the large-N limit\, it is shown to matc h with the expected results from string theory due to AdS/CFT duality\n\nM eeting ID: 946 1044 3637\nPasscode: 074360\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/23/ END:VEVENT BEGIN:VEVENT SUMMARY:Oleg Lunin (SUNY-Albany) DTSTART:20210407T150000Z DTEND:20210407T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/24 DESCRIPTION:Title: Supergravity excitations of stringy geometries\nby Oleg Lu nin (SUNY-Albany) as part of Theoretical and Mathematical Physics\n\n\nAbs tract\nMotivated by the desire to understand the dynamics of light modes o n various gravitational backgrounds\, this talk summarizes recent results concerning properties of scalar\, vector\, and tensor excitations of black holes and integrable stringy geometries.\n\nFor rotating black holes and for certain Wess-Zumino-Witten models\, full separability of all dynamical equations is demonstrated\, and symmetries underlying this property are u ncovered. For other classes of integrable backgrounds\, the energy spectra of various fields are evaluated\, and the algebraic constructions of the corresponding eigenfunctions are presented.\n\nMeeting ID: 973 8330 1111\n Passcode: 082472\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/24/ END:VEVENT BEGIN:VEVENT SUMMARY:Alexander Vikman (Institute of Physics of the Czech Academy of Sci ences\, Prague) DTSTART:20210414T150000Z DTEND:20210414T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/25 DESCRIPTION:Title: Losing the trace to discover dynamical Newton or Planck consta nts\nby Alexander Vikman (Institute of Physics of the Czech Academy of Sciences\, Prague) as part of Theoretical and Mathematical Physics\n\n\nA bstract\nI will discuss our recent work e-Print: 2011.07055. There we sho wed that promoting the trace part of the Einstein equations to a trivial identity results in the Newton constant being an integration constant. Thu s\, in this formulation the Newton constant is a global dynamical degree o f freedom which is also a subject to quantization\, quantum fluctuations a nd the Heisenberg uncertainty relations. This is similar to what happens to the cosmological constant in the unimodular gravity where the trace par t of the Einstein equations is lost in a different way. I will consider a constrained variational formulation of these modified Einstein equations. Then\, drawing on analogies with the Henneaux-Teitelboim action for unimod ular gravity\, I will discuss different general-covariant actions resultin g in these dynamics. In this approach\, it turned out that the inverse of the dynamical Newton constant is canonically conjugated to the Ricci scala r integrated over spacetime. Surprisingly\, instead of the dynamical Newto n constant one can formulate an equivalent theory with a dynamical Planck constant. Finally\, I will show that an axion-like field can play a role n ot only of the cosmological constant\, as in e-Print: 2001.03169\, but als o of the Newton constant or even of the Planck constant.\n\nMeeting ID: 95 3 6604 7713\nPasscode: 353336\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/25/ END:VEVENT BEGIN:VEVENT SUMMARY:Alberto Salvio (University of Rome Tor Vergata) DTSTART:20210421T150000Z DTEND:20210421T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/26 DESCRIPTION:Title: Models for a vast energy range: particles meet gravity and cos mology\nby Alberto Salvio (University of Rome Tor Vergata) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nI will discuss models valid over a vast energy range by following 2 strategies. In one approach (bottom-up) I will illustrate the main phenomenological aspects of a scena rio where one adds to the Standard Model 3 right-handed neutrinos and an a xion sector. This can account for neutrino oscillations\, dark matter\, ba ryogengesis\, inflation and can also stabilize the electroweak vacuum. In another\, more ambitious approach\, I will talk about a scenario where all couplings flow to zero at infinite energy (total asymptotic freedom). Th e corresponding phenomenology of this top-down approach will also be treat ed.\n\nMeeting ID: 977 1065 2931\nPasscode: 042219\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/26/ END:VEVENT BEGIN:VEVENT SUMMARY:David Osten (ITMP MSU\, Moscow) DTSTART:20210505T150000Z DTEND:20210505T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/27 DESCRIPTION:Title: Exceptional world-volume currents and their algebras\nby D avid Osten (ITMP MSU\, Moscow) as part of Theoretical and Mathematical Phy sics\n\n\nAbstract\nAfter a short review of exceptional generalised geomet ry I will introduce a unified setup for a duality-covariant Hamiltonian fo rmulation of world-volume theories of objects in string and M-theory. Base d on https://arxiv.org/abs/2103.03267\n\nMeeting ID: 981 6226 4274\nPassco de: 001440\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/27/ END:VEVENT BEGIN:VEVENT SUMMARY:Jorge Guillermo Russo (ICREA and University of Barcelona) DTSTART:20210512T150000Z DTEND:20210512T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/28 DESCRIPTION:Title: Thermal correlators in CFT and black holes\nby Jorge Guill ermo Russo (ICREA and University of Barcelona) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nWe describe the computation of thermal 2-point correlation functions in the black brane AdS5 background dual to 4d CFT's at finite temperature for operators of large scaling dimension. T his gives rise to a formula that matches the expected structure from the O PE. The thermal 2-point function has an exponentiation property\, whose or igin we explain. We also compute the first correction to the two-point fun ction due to graviton emission\, which encodes the time travel to the blac k hole singularity. We will also discuss some interesting features of high er-point functions.\n\nMeeting ID: 919 8499 0422\nPasscode: 268796\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/28/ END:VEVENT BEGIN:VEVENT SUMMARY:Edoardo Vescovi (KTH Royal Institute of Technology\, Stockholm Uni versity) DTSTART:20210519T150000Z DTEND:20210519T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/29 DESCRIPTION:Title: Probing boundary states at finite coupling\nby Edoardo Ves covi (KTH Royal Institute of Technology\, Stockholm University) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nIn this talk\, we cal culate exactly the correlation function of a Wilson loop operator and a lo cal non-BPS operator in planar N=4 SYM. First\, we introduce an effective theory for such observable in free theory and we reformulate the gauge-the ory computation as an overlap between an energy eigenstate of a spin-chain and a matrix product state. The form of the result supports the interpret ation of the correlator as an overlap between an integrable boundary state \, which we determine using symmetry and integrability\, and the state cor responding to the single-trace operator. Second\, we explain how to formul ate a non-perturbative bootstrap program based on the results obtained in this framework.\n\nMeeting ID: 919 8499 0422\nPasscode: 268796\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/29/ END:VEVENT BEGIN:VEVENT SUMMARY:Fedor Bezrukov (University of Manchester) DTSTART:20210526T150000Z DTEND:20210526T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/30 DESCRIPTION:Title: Inflation and reheating with Higgs inflation and related model s\nby Fedor Bezrukov (University of Manchester) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nUsing the Higgs field for inflati on is an economic way to solve two problems with one scalar field -- Higgs field is require in the Standard Model\, and a scalar field is the simple st method to drive inflation of the early Universe. However\, consistent attempt to do this takes us to the limits of validity of the quantum field theory\, and significant problems with the reheating after inflation. I ’ll discuss the ways to deal with this by combining the theory with R^2 gravitational terms\, and describe the highly nontrivial dynamics of the s ystem after inflation\n\nMeeting ID: 919 8499 0422\nPasscode: 268796\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/30/ END:VEVENT BEGIN:VEVENT SUMMARY:Angelos Fotopoulos (Northeastern University\, Boston) DTSTART:20210602T163000Z DTEND:20210602T173000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/31 DESCRIPTION:Title: Celestial CFT Correlators and Conformal Block Decomposition\nby Angelos Fotopoulos (Northeastern University\, Boston) as part of The oretical and Mathematical Physics\n\n\nAbstract\nI will shortly review the connection of the Bondi-van der Burg-Metzner-Sachs (BMS) symmetry group o f asymptotically flat four-dimensional spacetimes at null infinity to the S-matrix of elementary particles and gravitons. \nApplying Mellin transfor mations to traditional\, momentum space amplitudes we can compute celestia l amplitudes. These are conjectured to correspond to correlators of confor mal primary fields on a putative two-dimensional celestial sphere. I will elaborate on the proposal of flat holography in which four-dimensional phy sics is encoded in two-dimensional celestial conformal field theory (CCFT) . The symmetry underlying CCFT is the extended BMS symmetry of (asymptotic ally) flat spacetime. I will show how to use soft and collinear theorems o f Einstein-Yang-Mills theory to derive the OPEs of BMS field operators gen erating the symmetries of the BMS group\, superrotations and supertranslat ions. \nIn the second part of my talk\, time permitted\, I will discuss a proposal for radial quantization of the CCFT and I will present an attempt to decompose gluon celestial amplitudes in conformal blocks. This will re veal some very interesting aspects of the Celestial CFT: the emergence of new operators in the theory and space-time scattering channels which lead to continuous complex spin primary fields. The space-time interpretation o f these operators is still unclear. Moreover\, CFT crossing symmetry and i ts relation to four-dimensional spacetime crossing symmetry of the S-matri x are some interesting open problems.\n\nMeeting ID: 919 8499 0422\nPassco de: 268796\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/31/ END:VEVENT BEGIN:VEVENT SUMMARY:Kristiansen Lara (University of Santiago\, Chile) DTSTART:20210609T150000Z DTEND:20210609T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/32 DESCRIPTION:Title: Integrable Systems and Spacetime Dynamics\nby Kristiansen Lara (University of Santiago\, Chile) as part of Theoretical and Mathemati cal Physics\n\n\nAbstract\nIt is shown that the Ablowitz-Kaup-Newell-Segur (AKNS) integrable hierarchy can be obtained as the dynamical equations of three-dimensional General Relativity with a negative cosmological constan t. This geometrization of AKNS system is possible through the construction of novel boundary conditions for the gravitational field. These are invar iant under an asymptotic symmetry group characterized by an infinite set o f AKNS commuting conserved charges. Gravitational configurations are studi ed by means of $SL(2\,\\mathbb{R})$ conjugacy classes. Conical singulariti es and black hole solutions are included in the boundary conditions. Base d on https://arxiv.org/abs/2104.09676\n\nMeeting ID: 919 8499 0422\nPassco de: 268796\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/32/ END:VEVENT BEGIN:VEVENT SUMMARY:Shota Komatsu (CERN and IAS Princeton) DTSTART:20210616T150000Z DTEND:20210616T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/33 DESCRIPTION:Title: Comments on Large Charge and N=4 SYM\nby Shota Komatsu (CE RN and IAS Princeton) as part of Theoretical and Mathematical Physics\n\n\ nAbstract\nI will discuss three topics on the large charge limit of N=4 su per Yang-Mills and its holographic dual. First\, I will discuss what we ca n learn from holography about general structures of the large-charge expan sion of SCFT with higher-rank gauge groups. Second\, I will briefly discus s the double-scaling limit and their relation to the central extension of the symmetry. Third I will explain how the ideas from the large-charge exp ansion help to resolve confusions in the literature on the holographic com putation of correlation functions of heavy operators dual to D-branes in A dS.\n\nMeeting ID: 919 8499 0422\nPasscode: 268796\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/33/ END:VEVENT BEGIN:VEVENT SUMMARY:Alex Buchel (Perimeter Institute) DTSTART:20210922T150000Z DTEND:20210922T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/34 DESCRIPTION:Title: Black holes on a conifold with fluxes\nby Alex Buchel (Per imeter Institute) as part of Theoretical and Mathematical Physics\n\n\nAbs tract\nWe present a comprehensive analysis of the black holes on warped de formed conifold with fluxes in Type IIB supergravity. These black holes re alize the holographic dual to thermal states of the N = 1 supersymmetric S U(N) × SU(N + M) cascading gauge theory of Klebanov et al on round S^3 . There are three distinct mass scales in the theory: the strong coupling s cale Λ of the cascading gauge theory\, the compactification scale µ = 1/ L_3 (related to the S^3 radius L_3 ) and the temperature T of a thermal st ate. Depending on Λ \, µ and T \, there is an intricate pattern of confi nement/deconfinement (Hawking-Page) and the chiral symmetry breaking phase transitions.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/34/ END:VEVENT BEGIN:VEVENT SUMMARY:Eugeny Babichev (The University Paris-Saclay) DTSTART:20210929T150000Z DTEND:20210929T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/35 DESCRIPTION:Title: Black holes in scalar-tensor theories\nby Eugeny Babichev (The University Paris-Saclay) as part of Theoretical and Mathematical Phys ics\n\n\nAbstract\nI will review black hole solutions in Horndeski theory and its extensions. For shift symmetric theories of Horndeski and beyond H orndeski theory\, black holes involve several classes of nontrivial soluti ons: those that include\, at the level of the action\, a linear coupling t o the Gauss-Bonnet term and those that involve time dependence in the scal ar field. I will describe black hole solutions of both classes in some det ail. I will also review and discuss recent results on hairy black holes in particular subclasses of the theory.\n\nMeeting ID: 815 0976 8678\nPassco de: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/35/ END:VEVENT BEGIN:VEVENT SUMMARY:Victor Gorbenko (Stanford University) DTSTART:20211006T150000Z DTEND:20211006T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/36 DESCRIPTION:Title: Non-perturbative gravitational effects in cosmology\nby Vi ctor Gorbenko (Stanford University) as part of Theoretical and Mathematica l Physics\n\n\nAbstract\nI will start with reviewing some recent progress in understanding the black hole evaporation with the help of gravitational path integral methods. It turns out that for certain observables\, for ex ample the so-called Page curve for the BH entropy\, higher-topology saddle points of the gravitational path integral produce important and calculabl e contributions. I will then discuss potential applications of similar ide as in cosmology and when such non-perturbative effects may be relevant. Th en\, I will demonstrate a concrete calculation in a simple toy-model\, whe re a bra-ket wormhole\, that is a connection between the bra and the ket o f the wave function of the universe arises.\n\nMeeting ID: 815 0976 8678\n Passcode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/36/ END:VEVENT BEGIN:VEVENT SUMMARY:Kurt Hinterbichler (Case Western Reserve University) DTSTART:20211013T150000Z DTEND:20211013T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/37 DESCRIPTION:Title: Unitarization in Kaluza Klein theory and the Geometric Bootstr ap\nby Kurt Hinterbichler (Case Western Reserve University) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nThe infinite towers o f massive particles present in Kaluza Klein reductions of Einstein gravity conspire to soften the high-energy behavior of the scattering of massive spin-2 states. The mechanism by which this occurs leads to a bootstrap pr ocedure\, analogous to the conformal bootstrap\, that yields new non-trivi al constraints on the eigenvalue spectra of closed Einstein manifolds.\n\n Meeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/37/ END:VEVENT BEGIN:VEVENT SUMMARY:Dmitri Bykov (Steklov Mathematical Institute) DTSTART:20211020T150000Z DTEND:20211020T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/38 DESCRIPTION:Title: Sigma models as Gross-Neveu models\nby Dmitri Bykov (Stekl ov Mathematical Institute) as part of Theoretical and Mathematical Physics \n\n\nAbstract\nI will show that there is a wide class of integrable sigma models that are exactly and explicitly equivalent to bosonic Gross-Neveu models. In full generality these are models with quiver variety phase spac es\, but the familiar CP^n\, Grassmannian or flag manifold sigma models be long to this class as well. This approach leads to a new take on topics su ch as RG (Ricci) flow\, construction of integrable deformations and the in clusion of fermions. In particular\, it provides a way of obtaining worlds heet SUSY theories from target space SUSY theories by means of a supersymp lectic quotient.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/38/ END:VEVENT BEGIN:VEVENT SUMMARY:Andrei Parnachev (Trinity College Dublin) DTSTART:20211027T150000Z DTEND:20211027T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/39 DESCRIPTION:Title: Stress tensor and conformal correlators\nby Andrei Parnach ev (Trinity College Dublin) as part of Theoretical and Mathematical Physic s\n\n\nAbstract\nI will describe a calculation of the contributions of str ess tensor composites to correlators in CFTs (in d>2) with a large number of degrees of freedom\, including holographic CFTs. Implications for holo graphy\, thermalization and possible higher spin symmetries relevant for n ear lightcone correlators will be discussed.\n\nMeeting ID: 815 0976 8678\ nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/39/ END:VEVENT BEGIN:VEVENT SUMMARY:Mikhail Ivanov (Princeton\, IAS) DTSTART:20211103T150000Z DTEND:20211103T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/40 DESCRIPTION:Title: Love and Naturalness\nby Mikhail Ivanov (Princeton\, IAS) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nTidal Love numbers of a compact body capture multipole moments induced by external gr avitational fields. Also they appear as Wilson coefficients in the post-Ne wtonian effective field theory of extended objects. It has been known for a decade that Love numbers vanish identically for black holes in four dime nsions\, which posed a major naturalness problem in the EFT context. In my talk\, I will present a new hidden (“Love”) symmetry of black holes\, which elegantly resolves this naturalness paradox.\n\nMeeting ID: 815 097 6 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/40/ END:VEVENT BEGIN:VEVENT SUMMARY:Tommaso Macrelli (Surrey University) DTSTART:20211117T150000Z DTEND:20211117T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/41 DESCRIPTION:Title: Colour-kinematic duality\, double copy and homotopy algebras\nby Tommaso Macrelli (Surrey University) as part of Theoretical and Mat hematical Physics\n\n\nAbstract\nWhile colour-kinematic duality and double copy are a well established paradigm at tree level\, their loop level gen eralisation remained for a long time an unsolved problem. Lifting the on-s hell\, scattering amplitude-based description to an action-based approach\ , we show that a theory that exhibits tree level colour-kinematic duality can be reformulated in a way such that its loop integrands manifest colour -kinematic duality.\nAfter a review of Batalin-Vilkovisky formalism and ho motopy algebras\, we discuss how these structures emerge in quantum field theory and gravity. We focus then on the application of these sophisticate d mathematical tools to colour-kinematic duality and double copy\, introdu cing an adequate notion of colour-kinematic factorisation.\nThis talk is b ased on arXiv:2007.13803 [hep-th]\, arXiv:2102.11390 [hep-th]\, arXiv:2108 .03030 [hep-th].\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/41/ END:VEVENT BEGIN:VEVENT SUMMARY:Hongliang Jiang (Queen Mary University) DTSTART:20211124T150000Z DTEND:20211124T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/42 DESCRIPTION:Title: Infinite symmetries and Ward identities in celestial holograph y\nby Hongliang Jiang (Queen Mary University) as part of Theoretical a nd Mathematical Physics\n\n\nAbstract\nCelestial holography reformulates t he scattering amplitude holographically in terms of celestial conformal fi eld theory living at boundary null infinity\, thus opening up an interesti ng and promising avenue towards flat holography. In this talk\, I will di scuss various aspects of symmetry and their implications in celestial holo graphy. I will first discuss how to realize the global symmetry of spaceti me in celestial CFT\, ranging from Poincare to conformal symmetry\, and fu rther to the superconformal symmetry of N=4 SYM. Then I will study the asy mptotic symmetries from the celestial conformal field theory point of view . More specifically\, by focusing on the soft sector of celestial OPEs\, I will derive an infinite-dimensional symmetry algebra\, dubbed holography chiral algebra\, in supersymmetric Einstein-Yang-Mills theory. In the case of pure Einstein gravity\, the holography chiral algebra turns out to be the w_{1+∞} algebra. These infinite symmetries give rise to infinite Wa rd identities in celestial CFT\, which are equivalent to infinite soft the orems in scattering amplitudes. Finally\, I will also derive general form ulae for celestial OPEs and the corresponding Ward identities arising from arbitrary cubic interactions of three spinning massless particles.\n\nMee ting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/42/ END:VEVENT BEGIN:VEVENT SUMMARY:Nissan Itzhaki (Tel Aviv University) DTSTART:20211208T150000Z DTEND:20211208T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/43 DESCRIPTION:Title: A Puncture in the Euclidean Black Hole\nby Nissan Itzhaki (Tel Aviv University) as part of Theoretical and Mathematical Physics\n\n\ nAbstract\nWe consider the backreaction of the winding zero mode on the ci gar geometry. We focus on the case of the $SL(2\,R)_k/U(1)$ cigar associat ed with e.g. the near-horizon limit of $k$ NS5 black-branes. We solve the equations of motion numerically in the large $k$ limit as a function of th e amplitude of the winding mode at infinity. We find that there is a criti cal amplitude $C_c=\\exp(-\\gamma/2)$ that admits a critical solution. The exact CFT description of the $SL(2\,R)_k/U(1)$ cigar\, in particular the FZZ duality\, fixes completely the winding amplitude. We find that in the large $k$ limit there is an exact agreement $C_c=C_{FZZ}$.\nThe critical s olution is a cigar with a puncture at its tip\; consequently\, the BH entr opy is carried entirely by the winding condensate. We argue that\, in the Lorentzian case\, the information is ejected from the black hole through t his puncture.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/43/ END:VEVENT BEGIN:VEVENT SUMMARY:Monica Guica (Institute of Theoretical Physics\, Saclay) DTSTART:20220126T150000Z DTEND:20220126T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/44 DESCRIPTION:Title: $J\\bar T$ - deformed CFTs as non-local CFTs\nby Monica Gu ica (Institute of Theoretical Physics\, Saclay) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nI will start with a review of TTbar a nd JTbar - deformed CFTs and their holographic interpretation. I will then show that both TTbar and JTbar - deformed CFTs possess Virasoro x Virasor o symmetry. For the case of JTbar\, I will discuss the classical realizati on of these symmetries in terms of field-dependent coordinate transformati ons and show how the associated generators can be used to define an analog ue of "primary" operators in this non-local theory\, whose correlation fun ctions are entirely fixed in terms of those of the undeformed CFT.\n\nMeet ing ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/44/ END:VEVENT BEGIN:VEVENT SUMMARY:John F. Donoghue (University of Massachusetts) DTSTART:20220216T150000Z DTEND:20220216T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/45 DESCRIPTION:by John F. Donoghue (University of Massachusetts) as part of T heoretical and Mathematical Physics\n\n\nAbstract\nTBA\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/45/ END:VEVENT BEGIN:VEVENT SUMMARY:Barvinsky Andrei (Lebedev Institute) DTSTART:20220302T150000Z DTEND:20220302T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/46 DESCRIPTION:Title: Horava gravity as palladium of locality\, unitarity and renorm alizability: methods and results\nby Barvinsky Andrei (Lebedev Institu te) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nWe disc uss problems of covariant renormalization of Lorentz non-invariant Horava gravity models. Projectable version of these models in generic spacetime d imensions is shown to maintain UV renormalizability\, locality and unitari ty\, which is based on the BRST structure of renormalization in a special class of regular background covariant gauges. Renormalization group flow w ith the asymptotically free UV fixed point is presented in (2+1)-dimension al theory. Beta functions of (3+1)-dimensional theory are obtained by the combination of dimensional reduction and the method of universal functiona l traces. They feature fixed points with several candidates for asymptotic freedom and also suggest an intriguing connection between the (3+1)-dimen sional Horava gravity with detailed balance and gravitational Chern-Simons /topological massive gravity.\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/46/ END:VEVENT BEGIN:VEVENT SUMMARY:Fernando Quevedo (Cambridge University) DTSTART:20220323T150000Z DTEND:20220323T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/47 DESCRIPTION:Title: On moduli stabilisation\, de Sitter spacetime and inflation fr om string compactifications\nby Fernando Quevedo (Cambridge University ) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nAn overvi ew of the different attempts to stabilise the moduli fields\, measuring th e size and shape of the extra dimensions in string theory\, will be given. The extension of these techniques towards obtaining de Sitter spacetime a nd a period of early universe inflation will be highlighted\, emphasizing recent progress and open challenges.\n\nMeeting ID: 815 0976 8678\nPasscod e: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/47/ END:VEVENT BEGIN:VEVENT SUMMARY:Ellis Ye Yuan (Zhejiang University) DTSTART:20220330T150000Z DTEND:20220330T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/48 DESCRIPTION:Title: Graviton Scattering in AdS at Two Loops\nby Ellis Ye Yuan (Zhejiang University) as part of Theoretical and Mathematical Physics\n\n\ nAbstract\nI will present a preliminary result on the third-order correcti on in 1/N expansion to the four-point correlator of the stress tensor mult iplet in N=4 super Yang-Mills theory at large 't Hooft coupling\, which co rresponds to the two-loop scattering of four gravitons in the dual AdS5×S 5 supergravity. This is obtained by bootstrapping an educated ansatz based on intuitions from a hidden 10-dimensionthe conformal symmetry\, which I will describe in detail.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/48/ END:VEVENT BEGIN:VEVENT SUMMARY:Mikhail Shaposhnikov (EPFL Lausanne) DTSTART:20220406T150000Z DTEND:20220406T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/49 DESCRIPTION:Title: Anomaly-free scale symmetry and gravity\nby Mikhail Shapos hnikov (EPFL Lausanne) as part of Theoretical and Mathematical Physics\n\n \nAbstract\nWhat is the global symmetry of Nature? In the absence of gravi ty\, the most obvious answer to this question is given by special relativi ty and is associated with the Poincare transformations. As was noted a lon g time ago\, the free Maxwell equations have a wider symmetry group - the 15 parameters conformal invariance\, containing in addition to ten Poincar e generators\, four special conformal transformations\, and dilatations. D ilatations change the length of the rulers\, while special conformal trans formation can bend the lines but do not alter the angles between them. Cou ld it be that the symmetry of all interactions is conformal? We show that conformal symmetry can be made free from the quantum anomaly only in the f lat space. The presence of gravity would reduce the global symmetry group of the fundamental theory to the scale invariance only. We discuss how the effective Lagrangian respecting the scale symmetry can be used for the de scription of particle phenomenology and cosmology.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/49/ END:VEVENT BEGIN:VEVENT SUMMARY:Barak Gabai (Harvard University) DTSTART:20220413T150000Z DTEND:20220413T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/50 DESCRIPTION:Title: Exact quantization\nby Barak Gabai (Harvard University) as part of Theoretical and Mathematical Physics\n\n\nAbstract\n1d Hamiltonia n problems are classically-integrable by definition. A manifestation of th at is the fact that we can always use action-angle coordinates to parametr ize the phase space. A generalization of the action variables to QM is not immediately obvious. In the presentation I will explain how to define rig orous quantities that can be thought of as the quantum action variables an d how to write down an integral equation that determines their values\, fo r a large class of 1d Schrodinger problems. Then\, I will argue that these objects encode all of the dynamical information about the Quantum system\ , and explain how to extract the spectrum. The results are exact and rigor ous.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/50/ END:VEVENT BEGIN:VEVENT SUMMARY:Yuri Makeenko (ITEP\, Moscow) DTSTART:20220427T150000Z DTEND:20220427T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/51 DESCRIPTION:Title: How Pauli-Villars’ regularization tells the Nambu-Goto and P olyakov strings apart\nby Yuri Makeenko (ITEP\, Moscow) as part of The oretical and Mathematical Physics\n\n\nAbstract\nTBA\n\nMeeting ID: 815 09 76 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/51/ END:VEVENT BEGIN:VEVENT SUMMARY:Sergey Solodukhin (University of Tours) DTSTART:20220511T150000Z DTEND:20220511T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/52 DESCRIPTION:Title: Quantum states and their back-reacted geometries\nby Serge y Solodukhin (University of Tours) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nA black hole quantum state (Hartle-Hawking or Boul ware) is usually defined in a fixed background of a classical black hole. In my talk I will discuss the corresponding space-time geometry when the back-reaction is taken into account. The important questions include: does the back-reacted geometry always contain a horizon?\; how it depends on t he choice of the quantum state?\; and what is the right choice for the qu antum state for the non-physical fields such as ghosts? I will answer thes e and other questions in the context of a two-dimensional dilaton gravity. The talk is based on a joint recent work with D. Sarkar and Y. Potaux\, a rXiv:2112.03855.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/52/ END:VEVENT BEGIN:VEVENT SUMMARY:Dmitry Chicherin (Annecy LAPTH) DTSTART:20220518T150000Z DTEND:20220518T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/53 DESCRIPTION:Title: Null Wilson loop with Lagrangian insertion in N=4 super Yang-M ills theory\nby Dmitry Chicherin (Annecy LAPTH) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nNull Wilson loops in N = 4 super Yang-Mills are dual to planar scattering amplitudes. The duality holds at the level of their finite four-dimensional loop integrands as well as for the integrated observables with properly regularized infrared and cusp div ergences. We consider a closely related infrared-finite four-dimensional o bservable which interpolates between the integrand and the fully loop-inte grated quantity. It is defined as the null polygonal Wilson loop with a La grangian insertion normalized by the Wilson loop without insertion. Unlike the ratio and remainder functions of N = 4 super Yang-Mills amplitudes\, this observable is non-trivial already at four points and it is reminiscen t of finite parts of QCD amplitudes. We discuss the general structure of t his n-point observable at weak coupling. At n>4\, the loop corrections hav e rich kinematics. Indeed\, there are several leading singularities and th e accompanying loop functions are multivariable transcendental functions. We discuss a Grassmannian representation for the leading singularities and reveal their conformal and dual conformal symmetries. We conjecture a dua lity relation between the observable and the highest transcendentality pie ce of the planar all-plus amplitude in pure Yang-Mills theory. We test the duality using the one-loop n-point and two-loop four-point perturbative d ata for the observable. Relying on the duality\, we predict the highest we ight piece of the three-loop five-particle all-plus amplitude.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/53/ END:VEVENT BEGIN:VEVENT SUMMARY:Luca Cassia (Uppsala University) DTSTART:20220525T150000Z DTEND:20220525T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/54 DESCRIPTION:Title: q-Virasoro constraints and the algebra of Wilson loops in 3d\nby Luca Cassia (Uppsala University) as part of Theoretical and Mathema tical Physics\n\n\nAbstract\nThe BPS/CFT correspondence predicts that the partition function and other BPS observables in a 3d N=2 gauge theory can be mapped to states in a q-deformed CFT\, i.e. a theory whose symmetry alg ebra is q-Virasoro. Following this idea\, I will discuss how to derive q-V irasoro constraints for the generating function of 1/2-BPS Wilson loops fo r a family of 3d N=2 gauge theories.\nUnder certain assumptions on the Che rn--Simons level and the number of flavors the constraints can be solved e xactly and the solution can be recast as a "superintegrability" formula fo r characters of the gauge group. Moreover\, I will show that the same logi c can be applied to refined Chern--Simons theories and refined ABJ theorie s to derive formulas for refined knot invariants of the unknot. If time pe rmits I will also discuss the symmetries of the constraints and their phys ical interpretation as dualities of the gauge theory. The talk is based on https://arxiv.org/abs/2007.10354 and https://arxiv.org/abs/2107.07525.\n\ nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/54/ END:VEVENT BEGIN:VEVENT SUMMARY:Dmitry Ponomarev (ITMP MSU\, Moscow) DTSTART:20220601T150000Z DTEND:20220601T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/55 DESCRIPTION:Title: Invariant traces of the flat space chiral higher-spin algebra as scattering amplitudes\nby Dmitry Ponomarev (ITMP MSU\, Moscow) as p art of Theoretical and Mathematical Physics\n\n\nAbstract\nWe sum up two- and three-point amplitudes in the chiral higher-spin theory over helicitie s and find that these quite manifestly have the form of invariant traces o f the flat space chiral higher-spin algebra. We consider invariant traces of products of higher numbers of on-shell higher-spin fields and interpret these as higher-point scattering amplitudes. This construction closely mi mics its anti-de Sitter space counterpart\, which was considered some time ago and was confirmed holographically.\n\nMeeting ID: 815 0976 8678\nPass code: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/55/ END:VEVENT BEGIN:VEVENT SUMMARY:Euihun Joung (Kyung Hee University\, Seoul) DTSTART:20220608T150000Z DTEND:20220608T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/56 DESCRIPTION:Title: Colorful particles and fields in low dimensions\nby Euihun Joung (Kyung Hee University\, Seoul) as part of Theoretical and Mathemati cal Physics\n\n\nAbstract\nI will present a few recent applications of col orful extensions of spacetime symmetries to the theories of particles and fields in two and three dimensions. In particular\, the two dimensional BF theories is shown to reduce a colorful extension of Schwarzian theory.\n\ nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/56/ END:VEVENT BEGIN:VEVENT SUMMARY:Vasily Maslov (ITMP MSU\, Moscow) DTSTART:20221005T150000Z DTEND:20221005T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/57 DESCRIPTION:Title: An Effective Field Theory for Large Oscillons\nby Vasily M aslov (ITMP MSU\, Moscow) as part of Theoretical and Mathematical Physics\ n\n\nAbstract\nBased on arXiv:2208.04334. We consider oscillons - localize d\, quasiperiodic\, and extremely long-living classical solutions in model s with real scalar fields. We develop their effective description in the l imit of large size at finite field strength. Namely\, we note that nonline ar long-range field configurations can be described by an effective comple x field $\\psi(t\, \\mathbf{x})$ which is related to the original fields b y a canonical transformation. The action for $\\psi$ has the form of a sys tematic gradient expansion. At every order of the expansion\, such an effe ctive theory has a global U(1) symmetry and hence a family of stationary n ontopological solitons - oscillons. The decay of the latter objects is a n onperturbative process from the viewpoint of the effective theory. Our app roach gives an intuitive understanding of oscillons in full nonlinearity a nd explains their longevity. Importantly\, it also provides reliable selec tion criteria for models with long-lived oscillons. This technique is more precise in the nonrelativistic limit\, in the notable cases of nonlinear\ , extremely long-lived\, and large objects\, and also in lower spatial dim ensions. We test the effective theory by performing explicit numerical sim ulations of a (d+1)-dimensional scalar field with a plateau potential.\n\n Meeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/57/ END:VEVENT BEGIN:VEVENT SUMMARY:Sabir Ramamzanov (CEICO\, Prague) DTSTART:20221019T150000Z DTEND:20221019T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/58 DESCRIPTION:Title: Phase transitions in the dark Universe\nby Sabir Ramamzano v (CEICO\, Prague) as part of Theoretical and Mathematical Physics\n\n\nAb stract\nTypically phase transitions are associated with a constant scale o f symmetry breaking. In cosmology\, however\, a different situation is als o natural: the expectation value of a scalar field responsible for symmetr y breaking can be induced by its interactions with hot primordial plasma\, in which case the expectation value decreases as the Universe cools down. This picture can be realized in a simple renormalizable and approximately scale-invariant scenario. Non-trivial time-dependence of the symmetry bre aking scale enables new mechanisms of particle production at phase transit ions. These particles can be considered for the role of dark matter. Anoth er phenomenologically interesting outcome of phase transitions is formatio n of topological defects\, which serve as a source of potentially observab le gravitational waves. The latter can be used to probe the underlying mod el in a very weakly coupled regime inaccessible by other experiments.\n\nM eeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/58/ END:VEVENT BEGIN:VEVENT SUMMARY:Leonid Bork (ITEP\, Moscow) DTSTART:20221026T150000Z DTEND:20221026T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/59 DESCRIPTION:Title: Exact off-shell Sudakov form factor in N=4 SYM\nby Leonid Bork (ITEP\, Moscow) as part of Theoretical and Mathematical Physics\n\n\n Abstract\nWe consider the Sudakov form factor in N=4 SYM in the off-shell kinematical regime\, which can be achieved by considering the theory on it s Coulomb branch. We demonstrate that up two three loops both the infrared -divergent as well as the finite terms do exponentiate\, with the coeffici ent accompanying log’s of mass determined by the octagon anomalous dimen sion Γ_oct. This behaviour is in strike contrast to previous conjectural accounts in the literature. Together with the finite terms we observe that up to three loops the logarithm of the Sudakov form factor is identical t o twice the logarithm of the null octagon 𝕆_0\, which was recently intr oduced within the context of integrability-based approaches to four point correlation functions with infinitely-large R-charges. The null octagon 𝕆_0 is known in a closed form for all values of the 't Hooft coupling c onstant and kinematical parameters. We conjecture that the relation betwee n 𝕆_0 and the off-shell Sudakov form factor will hold to all loop order s.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/59/ END:VEVENT BEGIN:VEVENT SUMMARY:Alexander Ochirov (London Institute for Mathematical Sciences) DTSTART:20221102T150000Z DTEND:20221102T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/60 DESCRIPTION:Title: Chiral Approach to Massive Higher Spins\nby Alexander Ochi rov (London Institute for Mathematical Sciences) as part of Theoretical an d Mathematical Physics\n\n\nAbstract\nQuantum field theory of higher-spin particles is a formidable subject\, where preserving the physical number o f degrees of freedom in the Lorentz-invariant way requires a host of auxil iary fields. They can be chosen to have a rich gauge-symmetry structure\, but introducing consistent interactions in such approaches is still a non- trivial task\, with massive higher-spin Lagrangians specified only up to t hree points. In this talk\, I will discuss a new\, chiral description for massive higher-spin particles\, which in four spacetime dimensions allows to do away with the unphysical degrees of freedom. This greatly facilitate s the introduction of consistent interactions. I will concentrate on three theories\, in which higher-spin matter is coupled to electrodynamics\, no n-Abelian gauge theory or gravity. These theories are currently the only e xamples of consistently interacting field theories with massive higher-spi n fields.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/60/ END:VEVENT BEGIN:VEVENT SUMMARY:Francois Rondeau (the Sorbonne) DTSTART:20221109T150000Z DTEND:20221109T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/61 DESCRIPTION:Title: Intersecting D-brane models and the anomalous magnetic moment of the muon\nby Francois Rondeau (the Sorbonne) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nThe anomalous magnetic moment of the muon ($(g-2)_{\\mu}$) might be one of the most promising signals of ne w physics beyond the Standard Model (SM). The theoretical calculation pred icts a value smaller than the experimental measurement from the Brookhaven National Laboratory and Fermilab experiments\, with a standard deviation of $4.7\\sigma$. This talk will discuss recently proposed solutions to thi s discrepancy in the framework of low mass scale strings\, large extra dim ensions and intersecting D-brane physics.\n\nAfter reminding some basic as pects of intersecting D-brane models\, and in particular how the SM of par ticle physics can be obtained in this framework\, we will present two prop osals able to explain (part of) the observed discrepancy. They are based o n the contributions to the $(g-2)_{\\mu}$ coming from the Kaluza-Klein (KK ) states of the lepton number gauge boson\, corresponding to an open strin g tied to a leptonic $U(1)$ brane\, as well as from light scalars correspo nding to the first stringy excitations of an open string stretched between two D-branes intersecting with an ultra-small angle. In both cases\, we s how that there is a region of the parameter space compatible with the curr ent experimental bounds\, where these states can provide significant contr ibutions to the $(g-2)_{\\mu}$\, and fully or partially bridge the gap in the observed discrepancy. We then build the minimal D-brane configurations able to realise these two proposals.\n\nThe talk is based on 2110.01247\, 2112.07587 and 2209.11152.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098 \n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/61/ END:VEVENT BEGIN:VEVENT SUMMARY:Alexey Litvinov (Landau ITP\, Chernogolovka) DTSTART:20221116T150000Z DTEND:20221116T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/62 DESCRIPTION:Title: R-matrix formulation of affine Yangian of $\\hat{gl}(1|1)$ and integrable systems of N=2 superconformal field theory\nby Alexey Litv inov (Landau ITP\, Chernogolovka) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nWe study N=2 superconformal field theory and define the R-matrix which acts as an intertwining operator between different rea lisations of N=2W -algebras of type A. Using the R-matrix we define RLL al gebra and relate it to current realisation of affine Yangian of $\\hat{gl} (1|1)$. We also derive Bethe ansatz equations for the spectrum of integral s of motion.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/62/ END:VEVENT BEGIN:VEVENT SUMMARY:Yuya Kusuki (Caltech and Wako\, RIKEN) DTSTART:20221123T150000Z DTEND:20221123T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/63 DESCRIPTION:Title: AdS/BCFT from Bootstrap: Construction of Gravity with particle & brane\nby Yuya Kusuki (Caltech and Wako\, RIKEN) as part of Theoret ical and Mathematical Physics\n\n\nAbstract\nWe consider gravity with bran es and massive particles\, which has many unclear aspects. For example\, w e do not know how to understand some problematic configurations\, like bra ne self-intersections\, negative tension branes\, and spinning particles i nteracting with branes. We address these issues through AdS/BCFT. We solve a related conformal bootstrap and show that the self-intersection can be avoided by the black hole formation. We also reveal how to resolve the oth er problems in AdS/BCFT using the bootstrap.\nIn the later part\, we give the resolution of the same problems from the gravity side. For this purpos e\, we develop a simple way to construct gravity with branes and particles by cutting and pasting. The solution from this construction tells us how to resolve the issues from the gravity side\, which is completely consiste nt with the CFT result.\nAs a bonus\, we find a refined formula for the ho lographic Rényi entropy\, which appears to be crucial to correctly repro duce the boundary entropy term. We also find a holographic dual of boundar y primaries.\n\nMeeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/63/ END:VEVENT BEGIN:VEVENT SUMMARY:Carlo Heissenberg (Uppsala University and NORDITA) DTSTART:20221130T150000Z DTEND:20221130T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/64 DESCRIPTION:Title: Angular Momentum Loss Due to Tidal Effects in the Post-Minkows kian Expansion\nby Carlo Heissenberg (Uppsala University and NORDITA) as part of Theoretical and Mathematical Physics\n\n\nAbstract\nThe steadil y increasing sensitivity of gravitational-wave measurements challenges the state of the art of precision calculations for gravitational collisions. In this context\, scattering amplitudes have contributed to the advance of the precision frontier in the Post-Minkowskian (PM) expansion\, based on successive approximations labeled by powers of Newton's constant G and val id for generic velocities. In this talk\, based on arXiv:2210.15689\, I wi ll illustrate the calculation of tidal corrections to the loss of angular momentum in a two-body collision at leading Post-Minkowskian order from an amplitude-based approach. The eikonal operator allows us to efficiently c ombine elastic and inelastic amplitudes\, and captures both the contributi ons due to genuine gravitational-wave emissions and those due to the stati c gravitational field. We calculate the former by harnessing powerful coll ider-physics techniques such as reverse unitarity\, thereby reducing them to cut two-loop integrals. For the latter\, we can employ the results of a rXiv:2203.11915 where static-field effects were calculated for generic gra vitational scattering events using the leading soft graviton theorem.\n\nM eeting ID: 815 0976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/64/ END:VEVENT BEGIN:VEVENT SUMMARY:Anton Pribytok (Trinity College\, Dublin) DTSTART:20221207T150000Z DTEND:20221207T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/65 DESCRIPTION:Title: Automorphic symmetry and AdS String novel integrable deformati ons\nby Anton Pribytok (Trinity College\, Dublin) as part of Theoretic al and Mathematical Physics\n\n\nAbstract\nWe address the new structures a rising in quantum and string integrable theories\, as well as construct a method to find them. Initially we implement the automorphic symmetries on periodic lattice systems and exploit properties of an integrable hierarchy . This prescription is first applied for potentially new sl_2 sector\, Gen eralised Hubbard type classes and more. We then construct a boost recursio n for systems with R-/S-matrices that exhibit arbitrary spectral dependenc e\, which is also an apparent property of the scattering in AdS integrable backgrounds. The generalised bottom-up approach based on coupled differen tial systems is derived to resolve for R-matrices exactly. In addition\, o ne can isolate a special class of models (non-difference form) that provid e a new structure consistently arising in AdS_{3} and AdS_{2} string backg rounds. These classes can be proven to be represented as deformations of t he AdS_{2\,3} models\, which satisfy free fermion\, constraint\, braiding unitarity\, crossing and exhibit deformed algebraic structure that shares certain properties with AdS_3xSˆ3xMˆ4 and AdS_2xSˆ2xTˆ6 models. A rela ted discussion on further investigation of AdS_3 free fermion property\, T BA finite size corrections and GSE will be provided.\n\nMeeting ID: 815 09 76 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/65/ END:VEVENT BEGIN:VEVENT SUMMARY:Dionysios Anninos (King’s College London) DTSTART:20221214T150000Z DTEND:20221214T170000Z DTSTAMP:20260404T111214Z UID:ITMPseminar/66 DESCRIPTION:Title: Finite Features in Holography\nby Dionysios Anninos (King ’s College London) as part of Theoretical and Mathematical Physics\n\n\n Abstract\nWe consider theories of gravity where a more "finite" holographi c theory is relevant. From a Lorentzian perspective we comment on properti es of gravity in the presence of finite timelike boundaries\, and holograp hic realisations. Time permitting\, we also discuss Euclidean gravity on m anifolds with no boundary\, like Euclidean de Sitter.\n\nMeeting ID: 815 0 976 8678\nPasscode: 879098\n LOCATION:https://stable.researchseminars.org/talk/ITMPseminar/66/ END:VEVENT END:VCALENDAR