Simulation of Widom model kinetics for microemulsions

We introduce a “Kawasaki-type” spin-exchange dynamics for Widom's model of microemulsions, where the numbers of the molecules of oil, water and surfactants are conserved. We investigate the relaxation of concentration fluctuations in two dimensions, using this dynamics, and find diffusion for small-amplitude deviations from equilibrium. In addition we determine equilibrium concentrations, also in three dimensions, as a function of “field”.