Prof. Koenraad Schalm

20. April 2022.

You are cordially invited to the IPB COLLOQUIUM which will be held on Tuesday, 20 March 2018 at 11:00 in the “Zvonko Marić” lecture hall of the Institute of Physics Belgrade.

The talk entitled:

(Quantum) Chaos, hydrodynamics, and black hole scrambling

will be given by Prof. Koenraad Schalm (Lorentz Institute for Theoretical Physics, Leiden University, The Netherlands).

Abstract of the talk:

A concrete definition of chaos in quantum systems is a regime of exponential growth in a specific out-of-time-ordered correlator (OTOC). We will discuss this both in weakly coupled and in strongly coupled theories. In strongly coupled quantum theories with a holographic dual, the OTOC is directly related to probing the system’s hydrodynamic sound modes. The information contained in the OTOC is dual to a gravitational shock wave and this can be reconstructed in terms of purely diffusion-like gravitational waves at the horizon of a single-sided black hole with specific regularity-enforced imaginary values of frequency and momentum. The fact  that late-time equilibration and early-time chaos are controlled by the same dynamics is also a property of classical dilute gases. For weakly coupled systems, we show that the information contained in the OTOC follows from a Boltzmann kinetic equation for total energy exchange.