Self-similar equilibration of strongly interacting systems from holography

TL;DR

This paper investigates the equilibration process of strongly interacting 2+1 dimensional systems using holography, revealing a universal similarity solution that describes late-time behavior independent of initial conditions.

Contribution

It introduces a novel holographic model of far-from-equilibrium equilibration with a similarity solution capturing late-time dynamics in strongly coupled systems.

Findings

Equilibration described by a universal similarity solution.

Solution depends only on boundary conditions, not initial details.

Constructed via a single ordinary differential equation.

Abstract

We study the equilibration of a class of far-from-equilibrium strongly interacting systems using gauge/gravity duality. The systems we analyse are 2+1 dimensional and have a four dimensional gravitational dual. A prototype example of a system we analyse is the equilibration of a two dimensional fluid which is translational invariant in one direction and is attached to two different heat baths with different temperatures at infinity in the other direction. We realise such setup in gauge/gravity duality by joining two semi-infinite asymptotically Anti-de Sitter (AdS) black branes of different temperatures, which subsequently evolve towards equilibrium by emitting gravitational radiation towards the boundary of AdS. At sufficiently late times the solution converges to a similarity solution, which is only sensitive to the left and right equilibrium states and not to the details of the initial conditions. This attractor solution not only incorporates the growing region of equilibrated plasma but also the outwardly-propagating transition regions, and can be constructed by solving a single ordinary differential equation.