Talks

October 30 (Mon)


Slide: Link

Time: 09:30 - 11:00 (1hour 30min)

Title: Integrable boundaries from bootstrap and AdS/CFT

Abstract: In this pedagogical talk I will review the bootstrap approach for integrable quantum field theories putting special emphasis on integrable boundaries. I will provide the classification of integrable space ant time boundaries with su(2|2) symmetry and comment how they can be used to calculate various observables in the integrable AdS/(d)CFT correspondences.


Time: 14:00 - 15:00 (1hour)

Title: Quantized strings and instantons in holography

Abstract: I will present two examples where we compute worldsheet instanton contributions to the string partition function. In the first case, the string lives in a ten-dimensional background geometrically realized by spherical D4-branes and dual to maximally supersymmetric Yang-Mills on a five-dimensional sphere. In the second example the background is AdS4 x CP3, which is dual to ABJM in the type IIA limit. Our computations match non-perturbative corrections to the dual QFT free energy obtained via supersymmetric localization. If time allows, I will also discuss the extension of such analysis to semiclassical M2 brane partition functions in eleven-dimensional backgrounds, and their field theory duals.


Time: 17:00 - 18:00 (1hour)

Slide: Link

Title: Perturbative three-point functions and uniform transcendentality in N=4 SYM

Abstract: I report advances in the perturbative calculation of structure constants of twist-two operators with spins, and present all order conjectures on the transcendental degree and the perturbative structure of two- and three-point correlators of protected operators in N=4 SYM.

October 31 (Tue)


Slide: Link

Time: 09:30 - 11:00 (1hour 30min)

Title: Integrable monopoles


Slide: Link

Time: 14:00 - 15:00 (1hour)

Title: Hagedorn Transitions in Exact S-matrix theories with arbitrary spins

Abstract: Generalizing the quantum sine-Gordon and the sausage models, we construct exact $S$-matrices for higher spin  representations of quantum $su(2)_q$ symmetry, which satisfy unitarity, crossing-symmetry, and the Yang-Baxter equations.  We have derived the thermodynamic Bethe ansatz equations from this $S$-martrices and found that the universal kernel is  associated with graphs related to non-Dynkin diagrams. Furthermore, these equations are showing singularities in the free energies at some finite temperatures,  signaling the Hagedorn-type transitions.


Time: 17:00 - 18:00 (1hour)

Title: Wilson Loop Duality and OPE for Form Factors of Half-BPS Operators

Abstract: I will explain how to describe form factors of single-trace half-BPS operators in planar N=4 super Yang Mills theory using the T-dual Wilson loop picture. After reviewing earlier results for operators in the stress-tensor multiplet, I will present the dual Wilson loop description for the so-called MHV form factors of half-BPS operators. The general proposal relates these form factors to the matrix elements of a null periodic super Wilson loop with outgoing states composed of zero-momentum scalars. I will present perturbative tests of this description at weak coupling. I will then explain how to obtain exact result at finite coupling in the collinear limit using the Wilson loop Operator Product Expansion. I will conclude with general comments and speculations about form factors of unprotected operators such as the Konishi operator.

November 1 (Wed)


Slide: Link

Time: 09:30 - 10:30 (1hour)

Title: Origin Story for Amplitudes

Abstract: Perturbative scattering amplitudes in QCD and other gauge theories are very intricate analytic functions. Even in a simpler gauge theory such as planar N=4 super-Yang-Mills (SYM) theory, where they are known in some cases up to eight loops, they are complicated multiple polylogarithms (or worse). However, in special kinematic regions called origins, planar N=4 SYM maximally-helicity-violating amplitudes simplify enormously, to the exponential of a quadratic form in the logarithms of small variables. We propose a master formula for this expression. The dependence on the 't Hooft coupling employs a `tilted' version of the Beisert-Eden-Staudacher kernel for the cusp anomalous dimension, known exactly via integrability. The kinematic dependence can be understood from a strong-coupling analysis of the minimal area problem. Thus, origins provide a window into the exact coupling dependence of scattering amplitudes in planar N=4 SYM.


Slide: Link

Time: 11:00 - 12:00 (1hour)

Title: On beta-function of N=2 supersymmetric integrable sigma models

Abstract: We study regularization scheme dependence of N=2 supersymmetric integrable 2D sigma models. We conjecture that for certain integrable backgrounds such as complete T-dual of eta-deformed and lambda-deformed SU(N)/U(N-1) sigma models, there is a scheme in which the beta-function becomes one-loop exact. Namely, in this scheme the beta-function is given only by one-loop contribution up to the fourth loop, at which it is represented by the special terms contatining zeta_3, disappearing for the backgrounds mentioned above.


Slide: Link

Time: 14:00 - 15:30 (1hour 30min)

Title: Microscopic entanglement wedges from bilocal holography

Abstract: We review the holographic duality between the free O(N) vector model and higher spin gravity. Conserved spinning primary currents of the conformal field theory (CFT) are dual to spinning gauge fields in the gravity theory. Reducing to independent components of the conserved CFT currents one finds two components at each spin. After gauge fixing the gravity and then reducing to independent components, one finds two components of the gauge field at each spin. Collective field theory provides a systematic way to map between these two sets of degrees of freedom, providing a complete and explicit identification between the dynamical degrees of freedom of the CFT and the dual gravity. The resulting map exhibits many features expected of holographic duality: it provides a valid bulk reconstruction, it reproduces insights expected from the holography of information and it provides a microscopic derivation of entanglement wedge reconstruction. Finally, we also give a general argument suggesting the origin of holography in collective field theory description of gauge theory.


Slide: Link

Time: 17:00 - 18:00 (1hour)

Title: Approximate CFTs and Random Tensor Models

Abstract: Over the past few years, the importance of chaos in the physics of quantum black holes has become clear. This is particularly well understood in two-dimensional gravity, where the boundary system is quantum mechanics. Quantum chaos is well understood in quantum mechanics, going back several decades to the work of Wigner, in terms of random matrix universality: the statistical spectral correlations of a chaotic hamiltonian are indistinguishable from those of a random matrix drawn from the appropriate ensemble. Quantum chaos is much less understood in quantum (and conformal) field theories, which appear in top-down realizations of AdS/CFT. What is the right ensemble of theories to draw from in the case of field theories, similar to the random matrix ensembles of Wigner? In this talk, I will review progress on this front, and explain how to incorporate the many CFT constraints into a framework of ensemble of CFTs.

November 2 (Thu)


Time: 09:30 - 11:00 (1hour 30min)

Title: Integrability, spacetime dynamics and field theories

Abstract: In this talk I will review some recent developments connecting integrable models, soliton theory and field theories. The relationship between the AKNS hierarchy and anti-de Sitter three dimensional gravity will be discussed as well as integrable features of relativistic particles and complex solitons having real conserved quantities.


Time: 14:00 - 15:00 (1hour)

Title: A holographic quantization scheme in gravity 

Abstract: TBA


Time: 17:00 - 17:30 (30min)

Title: Turbulence and non-integrable motion of open string on AdS spacetime

Abstract: In this talk, we consider the dynamics of Nambu-Goto open-string on AdS3 spacetime. While it is well known that the motion of the closed string is integrable with an infinite number of charges, the motion of the open string can become non-integrable under some situations because the existence of a conserved charge depends on the boundary condition. In fact, we can find non-integrable dynamics, namely turbulence, under certain boundary condition. This implies that an open string on AdS3 can become non-integrable under the boundary condition.


Slide: Link

Time: 17:30 - 18:00 (30min)

Title: Inversion relations in integrable QFTs

Abstract: I will demonstrate the exact computation of vacuum Feynman diagrams' free energy in the thermodynamic limit using the inversion relation method, which relies on integrability. This quantity is connected to the critical coupling of QFTs that generate these Feynman diagrams. I will illustrate this derivation with the integrable 'brick wall' model. Finally, I will provide insights into its applicability to inhomogeneous Feynman graphs and other integrable candidate theories.

November 3 (Fri)


Time: 09:30 - 11:00 (1hour 30min)

Title: Giant correlators at quantum level

Abstract: TBA


Slide: Link

Time: 11:30 - 12:30 (1hour)

Title: Holography Beyond AdS from the worldsheet and TTbar

Abstract: In this talk, I'll talk about certain integrable deformations of worldsheet theory in AdS_3 supported by NS-NS flux that gives rise to string theory in backgrounds that asymptotes to flat spacetime with a linear dilaton. Because of the presence of the antisymmetric B-field, the Hilbert space contains states that are normalizable (bound states with discrete spectrum) and delta function normalizable (scattering states with continuous spectrum). I'm going to calculate the spectrum of these states, the one loop string partition function, and from it derive the long string density of states. I'll discuss certain interesting analytic properties of the one-loop partition sum. The theory on the long strings in these backgrounds forms a symmetric product. I'll compute the spectrum of these long strings and show that they give rise to the spectrum of Z_w twisted sector of the symmetric product of TTbar deformed CFT. I'll also show how to put a black hole in these backgrounds and talk about certain interesting features of black hole thermodynamics. Next, I'll construct operators of the boundary theory and compute their correlation functions. Finally, I'll talk about certain entanglement properties of the boundary theory.