Kinetics of phase ordering in the O(n) model with a conserved order parameter

Kinetics of inhomogeneous cooling in granular fluids

We study the dynamical behavior of a freely evolving granular gas, where the particles undergo inelastic collisions. The velocity and density fields exhibit complex pattern dynamics, which is reminiscent of phase ordering systems. For example, in the initial time regime, the density field stays (approximately) uniform, and the system is said to be in a homogeneous cooling state (HCS). At later times, the density field undergoes nonlinear clustering, and the system continues to lose energy in an inhomogeneous cooling state (ICS). We quantitatively characterize the HCS-->ICS crossover as a function of system parameters. Furthermore, we study nonlinear growth processes in the ICS by invoking analogies from studies of phase ordering dynamics.

Dynamics of phase separation in multicomponent mixtures

We study the dynamics of phase separation in multicomponent mixtures through Monte Carlo simulations of the q-state Potts model with conserved kinetics. We use the Monte Carlo renormalization-group method to investigate the asymptotic regime. The domain growth law is found to be consistent with the Lifshitz-Slyozov law, L(t) equivalent to t(1/3) (where t is time), regardless of the value of q. We also present results for the scaled correlation functions and domain-size distribution functions for a range of q values.

Nonequilibrium dynamics in the complex Ginzburg-Landau equation

Results from a comprehensive analytical and numerical study of nonequilibrium dynamics in the two-dimensional complex Ginzburg-Landau equation have been presented. In particular, spiral defects have been used to characterize the domain growth law and the evolution morphology. An asymptotic analysis of the single-spiral correlation function shows a sequence of singularities-analogous to those seen for time-dependent Ginzburg-Landau models with O(n) symmetry, where n is even.