Various Time-Scales of Relaxation

TL;DR

This paper investigates how different initial conditions affect the relaxation processes in a strongly coupled gauge theory using gauge-gravity duality, focusing on thermalization, scalar operator equilibration, and isotropization.

Contribution

It explores the impact of various initial configurations on multiple relaxation time-scales in a holographic model with anisotropy and scalar fields.

Findings

Different initial conditions influence the order and duration of relaxation processes.

The study identifies specific time-scales for thermalization, scalar equilibration, and isotropization.

Time ordering of relaxation processes depends on initial configurations.

Abstract

Via gauge-gravity duality, relaxation of far-from-equilibrium initial states in a strongly coupled gauge theory has been investigated. In the system we consider in this paper there are two ways where the state under study can deviate from its equilibrium: anisotropic pressure and time-dependent expectation value of a scalar operator with \Delta=3. In the gravity theory, this system corresponds to Einstein's general relativity with a non-trivial metric, including the anisotropy function, coupled to a massive scalar matter field. We study the effect of different initial configurations for scalar field and anisotropy function on physical processes such as thermalization, i.e. time evolution of event horizon, equilibration of the expectation value of scalar operator and isotropization. We also discuss time ordering of these time-scales.