Instabilities of an anisotropically expanding non-Abelian plasma: 1D+3V discretized hard-loop simulations

TL;DR

This paper numerically investigates the real-time evolution of instabilities in an anisotropically expanding non-Abelian plasma using lattice simulations, revealing nonlinear effects when instabilities grow large.

Contribution

It presents the first 1D+3V discretized hard-loop simulation of non-Abelian plasma instabilities in an expanding setting, extending previous semi-analytical Abelian results.

Findings

Reproduces semi-analytical Abelian regime results

Identifies nonlinear effects as instabilities grow

Provides insights into non-Abelian plasma dynamics

Abstract

Non-Abelian plasma instabilities play a crucial role in the nonequilibrium dynamics of a weakly coupled quark-gluon plasma and they importantly modify the standard perturbative bottom-up thermalization scenario in heavy-ion collisions. Using the auxiliary-field formulation of the hard-loop effective theory, we study numerically the real time evolution of instabilities in an anisotropic collisionless Yang-Mills plasma expanding longitudinally in free streaming. In this first real-time lattice simulation we consider the most unstable modes, long-wavelength coherent color fields that are constant in transverse directions and which therefore are effectively 1+1-dimensional in spacetime, except for the auxiliary fields which also depend on discretized momentum rapidity and transverse velocity components. We reproduce the semi-analytical results obtained previously for the Abelian regime and we determine the nonlinear effects which occur when the instabilities have grown such that non-Abelian interactions become important.