Spinodal Decomposition in Finite Temperature SU(2) and SU(3)

After a rapid increase in temperature across the deconfinement temperature T_d to temperatures T >> 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 < k < 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). For SU(3) at T near T_d, nucleation replaces spinodal decomposition as the dominant equilibration mechanism. Monte Carlo simulations of SU(2) and SU(3) lattice gauge theories exhibit the predicted phenomena. For SU(2), the observed value of k_c is in reasonable agreement with a value predicted from previous lattice measurements of m_D.