BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Joao Caetano (Stony Brook University) DTSTART:20201109T000000Z DTEND:20201109T010000Z DTSTAMP:20260404T094700Z UID:ttbar2020/1 DESCRIPTION:Title: Maximally Supersymmetric RG Flows in 4D and Integrability\nby Joao Caetano (Stony Brook University) as part of TTbar Deformation and In tegrability\n\n\nAbstract\nIn this talk\, we revisit the leading irrelevan t deformation of N=4 Super Yang-Mills theory that preserves sixteen superc harges. We consider the deformed theory on S3×R. We are able to write a c losed form expression of the classical action thanks to a formalism that r ealizes eight supercharges off shell. We then investigate integrability of the spectral problem\, by studying the spin-chain Hamiltonian in planar p erturbation theory. We also comment on the holographic interpretation of t he theory.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Akikazu Hashimoto (Wisconsin University) DTSTART:20201109T013000Z DTEND:20201109T023000Z DTSTAMP:20260404T094700Z UID:ttbar2020/2 DESCRIPTION:Title: Observables of TT-bar deformed CFTs and generalizations\nby A kikazu Hashimoto (Wisconsin University) as part of TTbar Deformation and I ntegrability\n\n\nAbstract\nFor a CFT deformed simultaneously by TT-bar\, JT-bar\, and TJ-bar\, I will describe two concrete physical observables. O ne is the torus partition function\, and the other is the entanglement ent ropy. I will also discuss some applications.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Alessandro Sfondrini (University of Padova) DTSTART:20201109T080000Z DTEND:20201109T090000Z DTSTAMP:20260404T094700Z UID:ttbar2020/3 DESCRIPTION:Title: T-Tbar deformations and string theory\nby Alessandro Sfondrin i (University of Padova) as part of TTbar Deformation and Integrability\n\ n\nAbstract\nIn this talk I will show how a T-Tbar transformation on the w orldsheet of a string non-linear sigma model can be interpreted as a TsT t ransformation of the target-space geometry.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Eoin O Colgain (APCTP) DTSTART:20201109T093000Z DTEND:20201109T103000Z DTSTAMP:20260404T094700Z UID:ttbar2020/4 DESCRIPTION:Title: From O(d\,d) to TTbar via Yang-Baxter deformations\nby Eoin O Colgain (APCTP) as part of TTbar Deformation and Integrability\n\n\nAbstr act\nSurprising synergies occur when research threads come to together. I will explain how AdS/CFT led to new insights on Yang-Baxter deformations\, which in turn led to new O(d\,d) transformations with non-constant entrie s. TTbar deformations in supergravity fall into the latter.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Mark Mezei (Stony Brook University) DTSTART:20201110T000000Z DTEND:20201110T010000Z DTSTAMP:20260404T094700Z UID:ttbar2020/5 DESCRIPTION:Title: TTbar-like theories and their symmetries\nby Mark Mezei (Ston y Brook University) as part of TTbar Deformation and Integrability\n\n\nAb stract\nThe solution of TTbar-deformed field theories opened a new window on the rich landscape of possible UV behaviors of quantum field theories. In this talk\, we describe attempts and partial successes in probing this landscape further by studying close relatives of the TTbar deformation. Th e symmetries preserved by these special irrelevant deformations will play a pivotal role in the discussion.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Song He (Jilin University) DTSTART:20201110T013000Z DTEND:20201110T023000Z DTSTAMP:20260404T094700Z UID:ttbar2020/6 DESCRIPTION:Title: Correlation function in TTbar deformed CFTs\nby Song He (Jili n University) as part of TTbar Deformation and Integrability\n\n\nAbstract \nIn this talk\, we will focus on the recent progresses on construction of the correlation functions in TTbar deformed theories in perturbative way. \n\nFirstly\, we will apply conformal Ward Identity and choose proper regu lization procedure to obtain the first order deformation of the correlatio n function in various situations. To go beyond the second order deformatio n\, one has to contain the TTbar flow effects and we explore a perturbativ e way to construct the correlation function\, in particular\, the second o rder deformation to the partition function in 2D free theories in terms of path integral formalism.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Roberto Tateo (Turin University) DTSTART:20201110T080000Z DTEND:20201110T090000Z DTSTAMP:20260404T094700Z UID:ttbar2020/7 DESCRIPTION:Title: A classical 4D generalisation of the TTbar-deformation\nby R oberto Tateo (Turin University) as part of TTbar Deformation and Integrabi lity\n\n\nAbstract\nTwo-dimensional field theories deformed by Zamolodchik ov's TTbar operator\nhave recently attracted the attention of theoretical physicists due to the\nmany important links with string theory and AdS/CF T.\nIn this talk\, I will describe various classical and quantum aspects o f\nthis particular irrelevant perturbation\, including its geometrical\n interpretation at the classical level.\n\nI will also introduce a general isation of this geometrical framework to\n4D field theories\, and discuss some of the interesting differences with\nthe 2D case.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Yunfeng Jiang (CERN) DTSTART:20201110T093000Z DTEND:20201110T103000Z DTSTAMP:20260404T094700Z UID:ttbar2020/8 DESCRIPTION:Title: TTbar deformed 1d Bose gas\nby Yunfeng Jiang (CERN) as part o f TTbar Deformation and Integrability\n\n\nAbstract\nTTbar deformation was originally proposed as an irrelevant deformation for 2d relativistic quan tum field theories. In this talk\, I will show that the same kind of integ rable deformation can be defined for a wide class of integrable models inc luding quantum spin chains and continuous integrable many-body systems suc h as the Lieb-Liniger model. I will present the definition for the TTbar d eformed 1d Bose gas and study its deformed spectrum and thermodynamics.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Vladimir Rosenhaus (IAS) DTSTART:20201111T000000Z DTEND:20201111T010000Z DTSTAMP:20260404T094700Z UID:ttbar2020/9 DESCRIPTION:Title: Integrability and renormalization under T \\\\bar T\nby Vlad imir Rosenhaus (IAS) as part of TTbar Deformation and Integrability\n\n\nA bstract\nSmirnov and Zamolodchikov recently introduced a new class of two- dimensional quantum field theories\, defined through a differential change of any existing theory by the determinant of the energy-momentum tensor. From this TT¯ flow equation one can find a simple expression for both the energy spectrum and the S-matrix of the TT¯ deformed theories. Our goal is to find the renormalized Lagrangian of the TT¯ deformed theories. In t he context of the TT¯ deformation of an integrable theory\, the deformed theory is also integrable and\, correspondingly\, the S-matrix factorizes into two-to-two S-matrices. One may thus hope to be able to extract the re normalized Lagrangian from the S-matrix. We do this explicitly for the TT ¯ deformation of a free massive scalar\, to second order in the deformati on parameter. Once one has the renormalized Lagrangian one can\, in princi ple\, compute all other observables\, such as correlation functions. We br iefly discuss this\, as well as the relation between the renormalized Lagr angian\, the TT¯ flow equation\, and the S-matrix.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Mitsuhiro Nishida (GIST) DTSTART:20201111T013000Z DTEND:20201111T023000Z DTSTAMP:20260404T094700Z UID:ttbar2020/10 DESCRIPTION:Title: Entanglement and Renyi Entropy of Multiple Intervals in TTbar De formed CFT and Holography\nby Mitsuhiro Nishida (GIST) as part of TTba r Deformation and Integrability\n\n\nAbstract\nWe study the entanglement e ntropy (EE) and the Renyi entropy (RE) of multiple intervals in two-dimens ional TTbar deformed conformal field theory (CFT) at finite temperature by field theoretic and holographic methods. First\, by the replica method wi th the twist operators\, we construct the general formula of the RE and EE up to the first order of a deformation parameter. By using our general fo rmula\, we show that the EE of multiple intervals for a holographic CFT is just a summation of the single interval case even with the small deformat ion. This is a non-trivial consequence from the field theory perspective\, though it may be expected by the Ryu-Takayanagi formula in holography. Ho wever\, the deformed RE of the two intervals is a summation of the single interval case only if the separations between the intervals are big enough . It can be understood by the tension of the cosmic branes dual to the RE. We also study the holographic EE for single and two intervals with an arb itrary cut-off radius (dual to the TTbar deformation) at any temperature. We confirm our holographic results agree with the field theory results wit h a small deformation and high temperature limit\, as expected. For two in tervals\, there are two configurations for EE: disconnected (s-channel) an d connected (t-channel) ones. We investigate the phase transition between them as we change parameters: as the deformation or temperature increases the phase transition is suppressed and the disconnected phase is more favo red.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Ioannis Papadimitriou (KIAS) DTSTART:20201111T080000Z DTEND:20201111T090000Z DTSTAMP:20260404T094700Z UID:ttbar2020/11 DESCRIPTION:Title: On AdS3 and AdS2 boundary conditions\nby Ioannis Papadimitri ou (KIAS) as part of TTbar Deformation and Integrability\n\n\nAbstract\nI will present a systematic analysis of AdS3 and AdS2 boundary conditions an d discuss their field theory interpretation.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Monica Guica (IPhT\, Saclay) DTSTART:20201111T093000Z DTEND:20201111T103000Z DTSTAMP:20260404T094700Z UID:ttbar2020/12 DESCRIPTION:by Monica Guica (IPhT\, Saclay) as part of TTbar Deformation a nd Integrability\n\nAbstract: TBA\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Van Raamsdonk (University of British Columbia) DTSTART:20201112T000000Z DTEND:20201112T010000Z DTSTAMP:20260404T094700Z UID:ttbar2020/13 DESCRIPTION:Title: Microscopic construction of Planck branes in AdS/CFT\nby Van Raamsdonk (University of British Columbia) as part of TTbar Deformation a nd Integrability\n\n\nAbstract\nIn this talk\, we describe BCFTs based on N=4 SYM theory on a half space which are dual to AdS5 x S5 with a dynamica l end-of-the-world brane cutting off the UV region of the geometry for hal f of the space. We argue that gravity is approximately localized to this e nd-of-the-world brane\, so it behaves as a Randall-Sundrum Planck brane. T he gravity picture has similarities to the proposed gravity dual of T-Tbar deformations for holographic theories.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Kyungkiu Kim (Sejong University) DTSTART:20201112T013000Z DTEND:20201112T020000Z DTSTAMP:20260404T094700Z UID:ttbar2020/14 DESCRIPTION:Title: More on Phase Transition in deformed JT Gravity\nby Kyungkiu Kim (Sejong University) as part of TTbar Deformation and Integrability\n\ nAbstract: TBA\n\nIn this paper we study a black hole phase transition not iced by Witten recently in a deformed JT gravity with an arbitrary potenti al. To investigate this transition\, we take into account geodesic and a t wo-point function. In the case with locally negative potentials\, the geod esic and the two-point function show signi\ncantly different behavior from those in cases with a positive potential. This behavior can be interprete d as a contribution from a metastable excitation induced by the negative p art of the potential. Also\, we consider charged black holes and construct the corresponding phase diagram in terms of the metastable excitation. Al so we study a map from this gravity model to CFT with a $Tbar{T}$ deformat ion.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Shinji Hirano (Wits University) DTSTART:20201112T080000Z DTEND:20201112T090000Z DTSTAMP:20260404T094700Z UID:ttbar2020/15 DESCRIPTION:Title: Random Geometry Approach to TTbar Deformation\nby Shinji Hir ano (Wits University) as part of TTbar Deformation and Integrability\n\n\n Abstract\nThe objective of my talk is twofold: One is to develop further C ardy's random geometry approch to the TTbar deformation. In particular\, i t is applied to the computation of correlators of the TTbar deformed CFTs\ , including 4pt functions of the stress tensor. A few key results are the TTbar deformed Liouville theory and a somewhat surprising logarithmic corr ection to a 4pt stress tensor correlator. The other is to discuss the grav ity dual of the TTbar deformed CFTs which becomes a straightforward applic ation of AdS/CFT from the random geometry perspective. A remark will be ma de on the relation to the cutoff AdS interpretation.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Kentaroh Yoshida (Kyoto University) DTSTART:20201112T093000Z DTEND:20201112T103000Z DTSTAMP:20260404T094700Z UID:ttbar2020/16 DESCRIPTION:Title: TTbar-deformation and Liouville gravity\nby Kentaroh Yoshida (Kyoto University) as part of TTbar Deformation and Integrability\n\n\nAb stract\nWe consider a gravitational perturbation of the Jackiw-Teitelboim (JT) gravity with an arbitrary dilaton potential and study the condition u nder which the quadratic action can be seen as a TTbar-deformation of the matter action. As a special case\, the flat-space JT gravity discussed by Dubovsky et al. [arXiv :1706 .06604] is included. Another interesting exam ple is a hyperbolic dilaton potential. This case is equivalent to a classi cal Liouville gravity with a negative cosmological constant and then a TTb ar-deformation of the matter action with a finite coupling is realized as a gravitational perturbation on AdS_2.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Jorrit Kruthoff (Stanford University) DTSTART:20201113T000000Z DTEND:20201113T010000Z DTSTAMP:20260404T094700Z UID:ttbar2020/17 DESCRIPTION:by Jorrit Kruthoff (Stanford University) as part of TTbar Defo rmation and Integrability\n\nAbstract: TBA\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/17/ END:VEVENT BEGIN:VEVENT SUMMARY:Yu Nakayama (Rikkyo University) DTSTART:20201113T013000Z DTEND:20201113T023000Z DTSTAMP:20260404T094700Z UID:ttbar2020/18 DESCRIPTION:Title: Very special TJ deformations\nby Yu Nakayama (Rikkyo Univers ity) as part of TTbar Deformation and Integrability\n\n\nAbstract\nTJ defo rmations of 2d CFT can be regarded as an analogue of one type of very spec ial relativity studied by Cohen and Glashow. Cohen and Glashow discussed how to add extra symmetry to study its phenomenological consequence (e.g. nutrino mass). I will study its analogue in d=2\, given by a very special TJ deformation.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/18/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin Doyon (King's College London) DTSTART:20201113T080000Z DTEND:20201113T090000Z DTSTAMP:20260404T094700Z UID:ttbar2020/19 DESCRIPTION:Title: TTbar deformations\, the width of fundamental particles\, and ge neralised hydrodynamics\nby Benjamin Doyon (King's College London) as part of TTbar Deformation and Integrability\n\n\nAbstract\nI will explain how TTbar deformations of many-body systems - both relativistic and Galile an invariant - can be seen as deformations of the fundamental particles of the theory. In this interpretation\, depending on the sign\, either the p articles gain a nonzero width - point particles become hard rods - or the space in-between them is made larger. This gives a simple explanation for the field-dependent change of coordinates that is known to reproduce TTbar deformations: it accounts for the reduced or enlarged free space. This al so clarifies many aspects of TTbar deformations\, such as their UV behavio urs and scattering matrix. Field-dependent changes of metric\, particle wi dths\, and their relation to scattering have been explored\, independently \, in the context of generalised hydrodynamics\, the hydrodynamic theory f or integrable systems. I will review aspects of this\, and explain some of the connections between the two areas of research. I will explain how TT bar deformations of many-body systems - both relativistic and Galilean inv ariant - can be seen as deformations of the fundamental particles of the t heory. In this interpretation\, depending on the sign\, either the particl es gain a nonzero width - point particles become hard rods - or the space in-between them is made larger. This gives a simple explanation for the fi eld-dependent change of coordinates that is known to reproduce TTbar defor mations: it accounts for the reduced or enlarged free space. This also cla rifies many aspects of TTbar deformations\, such as their UV behaviours an d scattering matrix. Field-dependent changes of metric\, particle widths\, and their relation to scattering have been explored\, independently\, in the context of generalised hydrodynamics\, the hydrodynamic theory for int egrable systems. I will review aspects of this\, and explain some of the c onnections between the two areas of research.\n\nBased on work in collabor ation with John Cardy.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Jong-Hyun Baek (Sejong University) DTSTART:20201112T020000Z DTEND:20201112T023000Z DTSTAMP:20260404T094700Z UID:ttbar2020/20 DESCRIPTION:Title: Holography of TTbar deformation in quantum mechanics\nby Jon g-Hyun Baek (Sejong University) as part of TTbar Deformation and Integrabi lity\n\n\nAbstract\nWe discuss the holographic interpretation of T^2 defor mation of quantum mechanical system. \nThe deformation can be thought of a s the dimensional reduction of TTbar deformation in 2d\, which preserves t he trace relation. \nThe 2d dual gravity theory is Jackiw-Teitelboim gravi ty\, which is a reduction of 3d Einstein gravity. \nThe variation principl e is employed to find the boundary conditions between deformed and undefor med theory. The mixed boundary conditions corresponds to Dirichlet boundar y conditions at finite cutoff via on-shell condition.\nThe trace of the de formed stress tensor in 2d gravity then reproduces the spectrum of the def ormed quantum mechanical system such as Schwarzian theory. \nWe also comm ent on the JTbar deformation in 1d.\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Changrim Ahn (Ewha Womans University) DTSTART:20201113T093000Z DTEND:20201113T103000Z DTSTAMP:20260404T094700Z UID:ttbar2020/21 DESCRIPTION:Title: Exact S-matrix and RG flow for Super-Liouville Theory with (TTba r)_s deformations\nby Changrim Ahn (Ewha Womans University) as part of TTbar Deformation and Integrability\n\nAbstract: TBA\n LOCATION:https://stable.researchseminars.org/talk/ttbar2020/21/ END:VEVENT END:VCALENDAR