Towards a hybrid Monte Carlo method for rarefied gas dynamics

For the Boltzmann equation, we present a hybrid Monte Carlo method that is robust in the fluid dynamic limit. The method is based on representing the solution as a convex combination of a non-equilibrium particle distribution and a Maxwellian. The hybrid distribution is then evolved by Monte Carlo with an unconditionally stable and asymptotic preserving time discretization. Some computational simulations of spatially homogeneous problems are presented here and extensions to spatially non homogeneous situations discussed.