Non-equilibrium steady state in the hydro regime

TL;DR

This paper investigates the formation and characteristics of non-equilibrium steady states in relativistic hydrodynamic systems with various equations of state, demonstrating the universality of steady state formation across different fluid types.

Contribution

It provides a theoretical analysis of non-equilibrium steady states in relativistic hydrodynamics with general EOS, including specific examples like holographic CFTs and barotropic fluids.

Findings

Steady states form universally in hydro regimes regardless of fluid type.

Explicit solutions for systems with linear EOS and holographic CFTs are obtained.

The results suggest a broad applicability of steady state formation in relativistic fluids.

Abstract

We study the existence and properties of the non-equilibrium steady state which arises by putting two copies of systems at different temperatures into a thermal contact. We solve the problem for the relativistic systems that are described by the energy-momentum of a perfect hydro with general equation of state (EOS). In particular, we examine several simple examples: a hydro with a linear EOS, a holographic CFT perturbed by a relevant operator and a barotropic fluid, i.e., P = P(E). Our studies suggest that the formation of steady state is a universal result of the hydro regime regardless of the kind of fluid.