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:20260422T212833Z UID:ttbar2020/1 DESCRIPTION:Title: Maximally Supersymmetric RG Flows in 4D and Integrability\nby Joao C aetano (Stony Brook University) as part of TTbar Deformation and Integrabi lity\n\n\nAbstract\nIn this talk\, we revisit the leading irrelevant defor mation of N=4 Super Yang-Mills theory that preserves sixteen supercharges. We consider the deformed theory on S3×R. We are able to write a closed f orm expression of the classical action thanks to a formalism that realizes eight supercharges off shell. We then investigate integrability of the sp ectral problem\, by studying the spin-chain Hamiltonian in planar perturba tion theory. We also comment on the holographic interpretation of the theo ry.\n LOCATION:https://researchseminars.org/talk/ttbar2020/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Akikazu Hashimoto (Wisconsin University) DTSTART:20201109T013000Z DTEND:20201109T023000Z DTSTAMP:20260422T212833Z UID:ttbar2020/2 DESCRIPTION:Title: Observables of TT-bar deformed CFTs and generalizations\nby Akikazu Hashimoto (Wisconsin University) as part of TTbar Deformation and Integrab ility\n\n\nAbstract\nFor a CFT deformed simultaneously by TT-bar\, JT-bar\ , and TJ-bar\, I will describe two concrete physical observables. One is t he torus partition function\, and the other is the entanglement entropy. I will also discuss some applications.\n LOCATION:https://researchseminars.org/talk/ttbar2020/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Alessandro Sfondrini (University of Padova) DTSTART:20201109T080000Z DTEND:20201109T090000Z DTSTAMP:20260422T212833Z UID:ttbar2020/3 DESCRIPTION:Title: T-Tbar deformations and string theory\nby Alessandro Sfondrini (Univ ersity of Padova) as part of TTbar Deformation and Integrability\n\n\nAbst ract\nIn this talk I will show how a T-Tbar transformation on the worldshe et of a string non-linear sigma model can be interpreted as a TsT transfor mation of the target-space geometry.\n LOCATION:https://researchseminars.org/talk/ttbar2020/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Eoin O Colgain (APCTP) DTSTART:20201109T093000Z DTEND:20201109T103000Z DTSTAMP:20260422T212833Z UID:ttbar2020/4 DESCRIPTION:Title: From O(d\,d) to TTbar via Yang-Baxter deformations\nby Eoin O Colgai n (APCTP) as part of TTbar Deformation and Integrability\n\n\nAbstract\nSu rprising synergies occur when research threads come to together. I will ex plain how AdS/CFT led to new insights on Yang-Baxter deformations\, which in turn led to new O(d\,d) transformations with non-constant entries. TTba r deformations in supergravity fall into the latter.\n LOCATION:https://researchseminars.org/talk/ttbar2020/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Mark Mezei (Stony Brook University) DTSTART:20201110T000000Z DTEND:20201110T010000Z DTSTAMP:20260422T212833Z UID:ttbar2020/5 DESCRIPTION:Title: TTbar-like theories and their symmetries\nby Mark Mezei (Stony Brook University) as part of TTbar Deformation and Integrability\n\n\nAbstract\ 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 landsca pe further by studying close relatives of the TTbar deformation. The symme tries preserved by these special irrelevant deformations will play a pivot al role in the discussion.\n LOCATION:https://researchseminars.org/talk/ttbar2020/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Song He (Jilin University) DTSTART:20201110T013000Z DTEND:20201110T023000Z DTSTAMP:20260422T212833Z UID:ttbar2020/6 DESCRIPTION:Title: Correlation function in TTbar deformed CFTs\nby Song He (Jilin Unive rsity) as part of TTbar Deformation and Integrability\n\n\nAbstract\nIn th is talk\, we will focus on the recent progresses on construction of the co rrelation functions in TTbar deformed theories in perturbative way.\n\nFir stly\, we will apply conformal Ward Identity and choose proper regulizatio n procedure to obtain the first order deformation of the correlation funct ion in various situations. To go beyond the second order deformation\, one has to contain the TTbar flow effects and we explore a perturbative way t o construct the correlation function\, in particular\, the second order de formation to the partition function in 2D free theories in terms of path i ntegral formalism.\n LOCATION:https://researchseminars.org/talk/ttbar2020/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Roberto Tateo (Turin University) DTSTART:20201110T080000Z DTEND:20201110T090000Z DTSTAMP:20260422T212833Z UID:ttbar2020/7 DESCRIPTION:Title: A classical 4D generalisation of the TTbar-deformation\nby Roberto Tateo (Turin University) as part of TTbar Deformation and Integrability\n\ n\nAbstract\nTwo-dimensional field theories deformed by Zamolodchikov's T Tbar operator\nhave recently attracted the attention of theoretical physic ists due to the\nmany important links with string theory and AdS/CFT.\nIn this talk\, I will describe various classical and quantum aspects of\nthis particular irrelevant perturbation\, including its geometrical\ninterpr etation at the classical level.\n\nI will also introduce a generalisation of this geometrical framework to\n4D field theories\, and discuss some of the interesting differences with\nthe 2D case.\n LOCATION:https://researchseminars.org/talk/ttbar2020/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Yunfeng Jiang (CERN) DTSTART:20201110T093000Z DTEND:20201110T103000Z DTSTAMP:20260422T212833Z UID:ttbar2020/8 DESCRIPTION:Title: TTbar deformed 1d Bose gas\nby Yunfeng Jiang (CERN) as part of TTbar Deformation and Integrability\n\n\nAbstract\nTTbar deformation was origin ally proposed as an irrelevant deformation for 2d relativistic quantum fie ld theories. In this talk\, I will show that the same kind of integrable d eformation can be defined for a wide class of integrable models including quantum spin chains and continuous integrable many-body systems such as th e Lieb-Liniger model. I will present the definition for the TTbar deformed 1d Bose gas and study its deformed spectrum and thermodynamics.\n LOCATION:https://researchseminars.org/talk/ttbar2020/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Vladimir Rosenhaus (IAS) DTSTART:20201111T000000Z DTEND:20201111T010000Z DTSTAMP:20260422T212833Z UID:ttbar2020/9 DESCRIPTION:Title: Integrability and renormalization under T \\\\bar T\nby Vladimir Ro senhaus (IAS) as part of TTbar Deformation and Integrability\n\n\nAbstract \nSmirnov and Zamolodchikov recently introduced a new class of two-dimensi onal quantum field theories\, defined through a differential change of any existing theory by the determinant of the energy-momentum tensor. From th is 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 f ind the renormalized Lagrangian of the TT¯ deformed theories. In the cont ext of the TT¯ deformation of an integrable theory\, the deformed theory is also integrable and\, correspondingly\, the S-matrix factorizes into tw o-to-two S-matrices. One may thus hope to be able to extract the renormali zed Lagrangian from the S-matrix. We do this explicitly for the TT¯ defor mation of a free massive scalar\, to second order in the deformation param eter. Once one has the renormalized Lagrangian one can\, in principle\, co mpute all other observables\, such as correlation functions. We briefly di scuss this\, as well as the relation between the renormalized Lagrangian\, the TT¯ flow equation\, and the S-matrix.\n LOCATION:https://researchseminars.org/talk/ttbar2020/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Mitsuhiro Nishida (GIST) DTSTART:20201111T013000Z DTEND:20201111T023000Z DTSTAMP:20260422T212833Z UID:ttbar2020/10 DESCRIPTION:Title: Entanglement and Renyi Entropy of Multiple Intervals in TTbar Deformed CFT and Holography\nby Mitsuhiro Nishida (GIST) as part of TTbar Defor mation and Integrability\n\n\nAbstract\nWe study the entanglement entropy (EE) and the Renyi entropy (RE) of multiple intervals in two-dimensional T Tbar deformed conformal field theory (CFT) at finite temperature by field theoretic and holographic methods. First\, by the replica method with 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 formula\, 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 deformation. Th is is a non-trivial consequence from the field theory perspective\, though it may be expected by the Ryu-Takayanagi formula in holography. However\, the deformed RE of the two intervals is a summation of the single interva l case only if the separations between the intervals are big enough. It ca n be understood by the tension of the cosmic branes dual to the RE. We als o study the holographic EE for single and two intervals with an arbitrary cut-off radius (dual to the TTbar deformation) at any temperature. We conf irm our holographic results agree with the field theory results with a sma ll deformation and high temperature limit\, as expected. For two intervals \, there are two configurations for EE: disconnected (s-channel) and conne cted (t-channel) ones. We investigate the phase transition between them as we change parameters: as the deformation or temperature increases the pha se transition is suppressed and the disconnected phase is more favored.\n LOCATION:https://researchseminars.org/talk/ttbar2020/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Ioannis Papadimitriou (KIAS) DTSTART:20201111T080000Z DTEND:20201111T090000Z DTSTAMP:20260422T212833Z UID:ttbar2020/11 DESCRIPTION:Title: On AdS3 and AdS2 boundary conditions\nby Ioannis Papadimitriou (KIA S) as part of TTbar Deformation and Integrability\n\n\nAbstract\nI will pr esent a systematic analysis of AdS3 and AdS2 boundary conditions and discu ss their field theory interpretation.\n LOCATION:https://researchseminars.org/talk/ttbar2020/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Monica Guica (IPhT\, Saclay) DTSTART:20201111T093000Z DTEND:20201111T103000Z DTSTAMP:20260422T212833Z UID:ttbar2020/12 DESCRIPTION:by Monica Guica (IPhT\, Saclay) as part of TTbar Deformation a nd Integrability\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/ttbar2020/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Van Raamsdonk (University of British Columbia) DTSTART:20201112T000000Z DTEND:20201112T010000Z DTSTAMP:20260422T212833Z UID:ttbar2020/13 DESCRIPTION:Title: Microscopic construction of Planck branes in AdS/CFT\nby Van Raamsd onk (University of British Columbia) as part of TTbar Deformation and Inte grability\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 dynamical end-o f-the-world brane cutting off the UV region of the geometry for half of th e space. We argue that gravity is approximately localized to this end-of-t he-world brane\, so it behaves as a Randall-Sundrum Planck brane. The grav ity picture has similarities to the proposed gravity dual of T-Tbar deform ations for holographic theories.\n LOCATION:https://researchseminars.org/talk/ttbar2020/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Kyungkiu Kim (Sejong University) DTSTART:20201112T013000Z DTEND:20201112T020000Z DTSTAMP:20260422T212833Z UID:ttbar2020/14 DESCRIPTION:Title: More on Phase Transition in deformed JT Gravity\nby Kyungkiu Kim (S ejong University) as part of TTbar Deformation and Integrability\n\nAbstra ct: TBA\n\nIn this paper we study a black hole phase transition noticed by Witten recently in a deformed JT gravity with an arbitrary potential. To investigate this transition\, we take into account geodesic and a two-poin t function. In the case with locally negative potentials\, the geodesic an d the two-point function show signi\ncantly different behavior from those in cases with a positive potential. This behavior can be interpreted as a contribution from a metastable excitation induced by the negative part of the potential. Also\, we consider charged black holes and construct the co rresponding phase diagram in terms of the metastable excitation. Also we s tudy a map from this gravity model to CFT with a $Tbar{T}$ deformation.\n LOCATION:https://researchseminars.org/talk/ttbar2020/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Shinji Hirano (Wits University) DTSTART:20201112T080000Z DTEND:20201112T090000Z DTSTAMP:20260422T212833Z UID:ttbar2020/15 DESCRIPTION:Title: Random Geometry Approach to TTbar Deformation\nby Shinji Hirano (Wi ts University) as part of TTbar Deformation and Integrability\n\n\nAbstrac t\nThe objective of my talk is twofold: One is to develop further Cardy's random geometry approch to the TTbar deformation. In particular\, it is ap plied to the computation of correlators of the TTbar deformed CFTs\, inclu ding 4pt functions of the stress tensor. A few key results are the TTbar d eformed Liouville theory and a somewhat surprising logarithmic correction to a 4pt stress tensor correlator. The other is to discuss the gravity dua l of the TTbar deformed CFTs which becomes a straightforward application o f AdS/CFT from the random geometry perspective. A remark will be made on t he relation to the cutoff AdS interpretation.\n LOCATION:https://researchseminars.org/talk/ttbar2020/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Kentaroh Yoshida (Kyoto University) DTSTART:20201112T093000Z DTEND:20201112T103000Z DTSTAMP:20260422T212833Z UID:ttbar2020/16 DESCRIPTION:Title: TTbar-deformation and Liouville gravity\nby Kentaroh Yoshida (Kyoto University) as part of TTbar Deformation and Integrability\n\n\nAbstract\ nWe consider a gravitational perturbation of the Jackiw-Teitelboim (JT) gr avity with an arbitrary dilaton potential and study the condition under wh ich 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 Dubovsk y et al. [arXiv :1706 .06604] is included. Another interesting example is a hyperbolic dilaton potential. This case is equivalent to a classical Lio uville gravity with a negative cosmological constant and then a TTbar-defo rmation of the matter action with a finite coupling is realized as a gravi tational perturbation on AdS_2.\n LOCATION:https://researchseminars.org/talk/ttbar2020/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Jorrit Kruthoff (Stanford University) DTSTART:20201113T000000Z DTEND:20201113T010000Z DTSTAMP:20260422T212833Z UID:ttbar2020/17 DESCRIPTION:by Jorrit Kruthoff (Stanford University) as part of TTbar Defo rmation and Integrability\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/ttbar2020/17/ END:VEVENT BEGIN:VEVENT SUMMARY:Yu Nakayama (Rikkyo University) DTSTART:20201113T013000Z DTEND:20201113T023000Z DTSTAMP:20260422T212833Z UID:ttbar2020/18 DESCRIPTION:Title: Very special TJ deformations\nby Yu Nakayama (Rikkyo University) as part of TTbar Deformation and Integrability\n\n\nAbstract\nTJ deformation s of 2d CFT can be regarded as an analogue of one type of very special rel ativity 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 defo rmation.\n LOCATION:https://researchseminars.org/talk/ttbar2020/18/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin Doyon (King's College London) DTSTART:20201113T080000Z DTEND:20201113T090000Z DTSTAMP:20260422T212833Z UID:ttbar2020/19 DESCRIPTION:Title: TTbar deformations\, the width of fundamental particles\, and generalis ed hydrodynamics\nby Benjamin Doyon (King's College London) as part of TTbar Deformation and Integrability\n\n\nAbstract\nI will explain how TTb ar deformations of many-body systems - both relativistic and Galilean inva riant - can be seen as deformations of the fundamental particles of the th eory. In this interpretation\, depending on the sign\, either the particle s gain a nonzero width - point particles become hard rods - or the space i n-between them is made larger. This gives a simple explanation for the fie ld-dependent change of coordinates that is known to reproduce TTbar deform ations: it accounts for the reduced or enlarged free space. This also clar ifies many aspects of TTbar deformations\, such as their UV behaviours and scattering matrix. Field-dependent changes of metric\, particle widths\, and their relation to scattering have been explored\, independently\, in t he context of generalised hydrodynamics\, the hydrodynamic theory for inte grable systems. I will review aspects of this\, and explain some of the co nnections between the two areas of research. I will explain how TTbar def ormations of many-body systems - both relativistic and Galilean invariant - can be seen as deformations of the fundamental particles of the theory. In this interpretation\, depending on the sign\, either the particles gain a nonzero width - point particles become hard rods - or the space in-betw een them is made larger. This gives a simple explanation for the field-dep endent change of coordinates that is known to reproduce TTbar deformations : it accounts for the reduced or enlarged free space. This also clarifies many aspects of TTbar deformations\, such as their UV behaviours and scatt ering matrix. Field-dependent changes of metric\, particle widths\, and th eir relation to scattering have been explored\, independently\, in the con text of generalised hydrodynamics\, the hydrodynamic theory for integrable systems. I will review aspects of this\, and explain some of the connecti ons between the two areas of research.\n\nBased on work in collaboration w ith John Cardy.\n LOCATION:https://researchseminars.org/talk/ttbar2020/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Jong-Hyun Baek (Sejong University) DTSTART:20201112T020000Z DTEND:20201112T023000Z DTSTAMP:20260422T212833Z UID:ttbar2020/20 DESCRIPTION:Title: Holography of TTbar deformation in quantum mechanics\nby Jong-Hyun Baek (Sejong University) as part of TTbar Deformation and Integrability\n\ n\nAbstract\nWe discuss the holographic interpretation of T^2 deformation of quantum mechanical system. \nThe deformation can be thought of as the d imensional reduction of TTbar deformation in 2d\, which preserves the trac e relation. \nThe 2d dual gravity theory is Jackiw-Teitelboim gravity\, wh ich is a reduction of 3d Einstein gravity. \nThe variation principle is em ployed to find the boundary conditions between deformed and undeformed the ory. The mixed boundary conditions corresponds to Dirichlet boundary condi tions at finite cutoff via on-shell condition.\nThe trace of the deformed stress tensor in 2d gravity then reproduces the spectrum of the deformed q uantum mechanical system such as Schwarzian theory. \nWe also comment on the JTbar deformation in 1d.\n LOCATION:https://researchseminars.org/talk/ttbar2020/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Changrim Ahn (Ewha Womans University) DTSTART:20201113T093000Z DTEND:20201113T103000Z DTSTAMP:20260422T212833Z UID:ttbar2020/21 DESCRIPTION:Title: Exact S-matrix and RG flow for Super-Liouville Theory with (TTbar)_s de formations\nby Changrim Ahn (Ewha Womans University) as part of TTbar Deformation and Integrability\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/ttbar2020/21/ END:VEVENT END:VCALENDAR