Koenraad Schalm (Leiden University)

Title: “Detecting chaos in hydrodynamics”

Abstract:
Hydrodynamics assumes local equilibration and equilibration assumes ergodic mixing driven by chaos — at least in semi-classical systems. For a generic such system the timescales of macroscopic thermalization and onset of microscopic chaos are very different. Nevertheless, it is a pillar of Boltzmann transport that long-time equilibration can be computed from microscopic dynamics. We show how in these systems the two timescales are in fact related. Moreover, we show that a similar connection between both scales surprisingly also exists in extremely strongly coupled systems through a phenomenon christened pole-skipping in hydrodynamic response.