Finite Temperature QCD Interfaces Out of Equilibrium

TL;DR

This paper investigates the behavior of interfaces in non-equilibrium finite temperature QCD by combining theoretical models with Monte Carlo simulations, revealing both continuous and discontinuous phase transitions influenced by temperature gradients.

Contribution

It introduces a density matrix approach with space-dependent temperature and analyzes interface behavior in non-equilibrium QCD, supported by Monte Carlo simulations and perturbation theory.

Findings

Monte Carlo simulations show both continuous and discontinuous interfacial behaviors.

Perturbation theory predicts a universal high-temperature profile.

Temperature gradients induce new terms affecting the order parameter.

Abstract

The properties of interfaces in non-equilibrium situations are studied by constructing a density matrix with a space-dependent temperature. The temperature gradient gives rise to new terms in the equation for the order parameter. Surface terms induced in effective actions by abrupt temperature changes provide a natural theoretical framework for understanding the occurence of both continuous and discontinuous behavior in the order parameter. Monte Carlo simulation of pure QCD shows both kinds of interfacial behavior. Perturbation theory predicts a universal profile in the high temperature phase, which can be tested by Monte Carlo simulation.