Kinetics of Phase Transitions in Quark Matter

We study the kinetics of chiral transitions in quark matter using a phenomenological framework (Ginzburg-Landau model). We focus on the effect of inertial terms on the coarsening dynamics subsequent to a quench from the massless quark phase to the massive quark phase. The domain growth process shows a crossover from a fast inertial regime [with $L(t) \sim t (\ln t)^{1/2}$] to a diffusive Cahn-Allen regime [with $L(t)\sim t^{1/2}$].Comment: 17 pages with 4 figures. Published in Euro Physics Letters (EPL). arXiv admin note: substantial text overlap with arXiv:1209.6137, arXiv:1101.050

Ordering dynamics of self-propelled particles in an inhomogeneous medium

Ordering dynamics of self-propelled particles in an inhomogeneous medium in two-dimensions is studied. We write coarse-grained hydrodynamic equations of motion for coarse-grained density and velocity fields in the presence of an external random disorder field, which is quenched in time. The strength of inhomogeneity is tuned from zero disorder (clean system) to large disorder. In the clean system, the velocity field grows algebraically as $L_{\rm V} \sim t^{0.5}$. The density field does not show clean power-law growth; however, it follows $L_{\rm \rho} \sim t^{0.8}$ approximately. In the inhomogeneous system, we find a disorder dependent growth. For both the density and the velocity, growth slow down with increasing strength of disorder. The velocity shows a disorder dependent power-law growth $L_{\rm V}(t,\Delta) \sim t^{1/\bar z_{\rm V}(\Delta)}$ for intermediate times. At late times, there is a crossover to logarithmic growth $L_{\rm V}(t,\Delta) \sim (\ln t)^{1/\varphi}$, where $\varphi$ is a disorder independent exponent. Two-point correlation functions for the velocity shows dynamical scaling, but the density does not