Derivation of a Non-Local Model for Diffusion Asymptotics; Application to Radiative Transfer Problems

In this paper we introduce a new closure which provides consistent models intermediate between the full kinetic description and the corresponding diffusion limit. This closure is of non local type in the sense that it involves pseudo-differential operators. We propose numerical approximations to treat such non local terms. We apply the whole strategy to the system of radiative hydrodynamics in the non equilibrium regime.