Equilibration of a strongly interacting plasma: holographic analysis of local and nonlocal probes

TL;DR

This paper investigates how a strongly coupled plasma relaxes to equilibrium by analyzing local and nonlocal observables via holography, revealing a hierarchy in thermalization times based on probe scales.

Contribution

It introduces a holographic framework to study the thermalization process of a strongly interacting plasma, focusing on the evolution of various probes after a boundary spacetime quench.

Findings

Shorter scale probes thermalize faster.

Hierarchy in thermalization times among different observables.

Black hole horizon dynamics relate to plasma relaxation.

Abstract

The relaxation of a strongly coupled plasma towards the hydrodynamic regime is studied by analyzing the evolution of local and nonlocal observables in the holographic approach. The system is driven in an initial anisotropic and far-from equilibrium state through an impulsive time-dependent deformation (quench) of the boundary spacetime geometry. Effective temperature and entropy density are related to the position and area of a black hole horizon, which has formed as a consequence of the distortion. The behavior of stress-energy tensor, equal-time correlation functions and Wilson loops of different shapes is examined, and a hierarchy among their thermalization times emerges: probes involving shorter length scales thermalize faster.