Spinodal Decomposition in High Temperature Gauge Theories

TL;DR

This paper investigates the phenomenon of spinodal decomposition in high-temperature pure gauge theories, showing how unstable long-wavelength fluctuations drive the approach to equilibrium, with Monte Carlo simulations supporting theoretical predictions.

Contribution

It demonstrates the occurrence of spinodal decomposition in pure gauge theories at high temperatures and compares simulation results with theoretical predictions of the unstable mode range.

Findings

Unstable modes occur for wave vectors up to approximately the Debye mass.

Monte Carlo simulations confirm the predicted unstable mode range.

Nucleation may dominate over spinodal decomposition near the deconfinement temperature.

Abstract

After a rapid increase in temperature across the deconfinement temperature $% T_{d}$, pure gauge theories exhibit unstable long wavelength fluctuations in the approach to equilibrium. This phenomenon is analogous to spinodal decomposition observed in condensed matter physics, and also seen in models of disordered chiral condensate formation. At high temperature, the unstable modes occur only in the range $0\leq k$ $\leq k_{c}$, where $k_{c}$ is on the order of the Debye screening mass $m_D$. Equilibration always occurs via spinodal decomposition for $SU(2) $at temperatures $T>T_{d}$ and for SU(3) for $T\gg T_{d}$. For SU(3) at temperatures $T\gtrsim T_{d}$, nucleation may replace spinodal decomposition as the dominant equilibration mechanism. Monte Carlo simulations of SU(2) lattice gauge theory exhibit the predicted phenomena. The observed value of $k_c$ is in reasonable agreement with a value predicted from previous lattice measurements of $m_D$.