Equilibration in an interacting field theory

We use a combination of perturbation theory and numerical techniques to study the equilibration of two interacting fields that are initially at thermal equilibrium at different temperatures. Using standard rules of quantum field theory, we examine the master equations that describe the time evolution of the distribution functions for the two coupled systems. By making a few reasonable assumptions we reduce the resulting coupled integral/differential equations to a pair of differential equations that can be solved numerically relatively easily and which give physically sensible results.