Laws of large numbers for mesoscopic stochastic models of reacting and diffusing particles

We study the asymptotic behaviour of some mesoscopic stochastic models for systems of reacting and diffusing particles (also known as density-dependent population processes) as the number of particles goes to infinity. Our approach is related to the variational approach to solving the parabolic partial differential equations that arise as limit dynamics. We first present a result for a model that converges to a classical system of reaction-diffusion equations. In addition, we discuss two models with nonlinear diffusion that give rise to quasilinear parabolic equations in the limit