Far-from-equilibrium dynamics of a strongly coupled non-Abelian plasma with non-zero charge density or external magnetic field

TL;DR

This study uses holography to analyze how a strongly coupled plasma with charge density or magnetic field equilibrates, finding that the process is mainly influenced by initial conditions rather than external fields.

Contribution

It demonstrates that the equilibration dynamics of a strongly coupled plasma are largely unaffected by large charge densities or magnetic fields, emphasizing the role of initial conditions.

Findings

Equilibration time is primarily determined by initial departure from equilibrium.

External magnetic fields and charge densities have minimal impact on equilibration dynamics.

A simple model accurately predicts equilibration times for localized initial deviations.

Abstract

Using holography, we study the evolution of a spatially homogeneous, far from equilibrium, strongly coupled N=4 supersymmetric Yang-Mills plasma with a non-zero charge density or a background magnetic field. This gauge theory problem corresponds, in the dual gravity description, to an initial value problem in Einstein-Maxwell theory with homogeneous but anisotropic initial conditions. We explore the dependence of the equilibration process on different aspects of the initial departure from equilibrium and, while controlling for these dependencies, examine how the equilibration dynamics are affected by the presence of a non-vanishing charge density or an external magnetic field. The equilibration dynamics are remarkably insensitive to the addition of even large chemical potentials or magnetic fields; the equilibration time is set primarily by the form of the initial departure from equilibrium. For initial deviations from equilibrium which are well localized in scale, we formulate a simple model for equilibration times which agrees quite well with our results.