Arrival & check-in

Talk 1 - Sašo Grozdanov 

The spectral duality relation 

Abstract: 

Lunch

Talk 2 - Maria Knysh

Krylov exponents and power spectra for maximal quantum chaos: an EFT approach

Abstract: In this talk, we revisit the effective field theory (EFT) description of maximal chaos for systems at finite temperature based on quantum hydrodynamics through the lens of Krylov complexity and the Universal Operator Growth Hypothesis to test the relationship between two measures of quantum chaos: out-of-time-ordered correlators (OTOCs) and Krylov complexity. In the EFT, a shift symmetry of the hydrodynamic modes enforces the maximal Lyapunov exponent in OTOCs, $\lambda_L = 2\pi T$, and simultaneously constrains thermal two-point autocorrelators. By solving these constraints for multiple examples and computing the associated Lanczos coefficients and Krylov exponents, we identify cases that exhibit a submaximal Krylov exponent, $\lambda_K = \lambda_L/2$. This suggests a tension with the conjectured bound $\lambda_L \leq \lambda_K \leq 2\pi T$ for finite temperatures, highlighting subtleties in how the EFT to captures operator growth.

Talk 3 - Adrian Sanchez-Garrido 

Black hole formation from the operator product expansion

Abstract:  In this talk I will present work in progress with P. Chowdhury, F. Haehl and Y. Zhao, where we are studying the conformal field theory dual to the process of black hole formation in AdS3 out of the collision of two shockwaves. In particular, using tools related to the Virasoro fusion kernel, we have determined numerically that the OPE block corresponding to the fusion of the two operators that source the shockwaves is dominated by the contribution of some primary operator whose scaling dimension takes a value that grows initially exponentially as a function of the source time in a specific coordinate patch, in a way such that it reaches the black hole threshold at a time scale proportional to the scrambling time, signalling black hole formation. I will present the preliminary results of this ongoing analysis and discuss their relation to operator growth and to the corresponding black hole formation condition in three-dimensional gravity. 

Coffee

Talk 4 - Edgar Shaghoulian

Conformal boundary conditions in gravity and a holographic dual

Abstract:  I will discuss conformal boundary conditions in gravity, reviewing the surprising thermodynamics that results in flat, anti-de Sitter, and de Sitter spacetimes. I will then focus on AdS3 spacetime, where I will propose a holographic dual theory to this finite cutoff system. The dual theory consists of deforming timelike Liouville theory by an exactly marginal operator, which in the pure gravity sector corresponds to the gravitationally dressed TTbar operator. Work with Allameh, Banihashemi, and Shashi.

Discussion with speakers of day 1

Talk 5 - Amos Chan 

Many-Body Quantum Chaos and the Spectral Form Factor

Abstract: The study of spectral statistics is of importance in physics due to its simplicity, universality, and utility as a diagnosis of quantum chaos and localization. Recently, as a probe of spectral statistics, the spectral form factor (SFF) has been instrumental  in discovering the random matrix theory behaviour of black holes [1], in pinpointing novel signatures of quantum chaos in the presence of many-body interactions [2], and in providing insights on the existence of the many-body localization phase in the thermodynamic limit [3]. In this talk, I will provide an overview of the generic behavior of the SFF in closed [4] and open [5] strongly interacting many-body quantum chaotic systems, along with its experimental measurement in quantum simulators [6]. In particular, I will present a statistical mechanical mapping between the SFF of quantum many-body chaotic systems and the partition function of classical ferromagnetic spin chains. If time permits, I will also discuss how non-Hermitian random matrix universality can emerge from Hermitian quantum many-body chaotic systems.

Talk 6 - Silvia Georgescu 

Title:  Symmetries and non-locality in warped AdS3 holography

Abstract: Warped AdS3 backgrounds provide set-ups to study holography beyond AdS and, in particular, holography for near-extremal Kerr black holes. In this talk, we focus on asymptotic symmetries of warped AdS3 backgrounds. It was recently argued that a (1,2) deformation of 2d CFTs, the JTbar deformation, captures features of the near-horizon geometry of near-extremal Kerr black holes and of certain warped AdS3 backgrounds. JTbar deformed CFTs have infinite dimensional symmetry algebras. In a basis in which the symmetry generators act non-locally, the algebra consists of two commuting copies of the Virasoro-U(1)KM algebra. We encounter the same symmetry algebra for certain warped BTZ backgrounds constructed in string theory.

Talk 7 - Thomas Colas

An open system approach to gravity

Abstract: Several open problems in cosmology — including the nature of inflation, dark matter, and dark energy — involve spacetime-filling media with unknown microphysics, and can be probed so far only through their gravitational effects. This observation motivates a systematic open-system approach, in which gravity evolves in the presence of a generic, unobservable environment. In this talk, I will present a general framework for open gravitational dynamics based on General Relativity and the Schwinger-Keldysh formalism. As an application, I will describe the most general conservative and dissipative dynamics of scalar and tensor perturbations during single-clock inflation. I will conclude by exploring possible connections with holography

Lunch

Discussion with speakers of day 2