Evolution of interfaces and expansion in width

Abstract

Interfaces in a model with a single, real nonconserved order parameter and purely dissipative evolution equation are considered. We show that a systematic perturbative approach, called the expansion in width and developed for curved domain walls, can be generalized to the interfaces. Procedure for calculating curvature corrections is described. We also derive formulas for local velocity and local surface tension of the interface. As an example, evolution of spherical interfaces is discussed, including an estimate of critical size of small droplets.

Discussion of stability of the interface is added, and the numerical estimates of width and velocity of the interface in the liquid crystal example are corrected. 25 pages, Latex2e