Kinetics of Granular Gases

It is shown how the Boltzmann equation corresponding to a model granular gas can be systematically analyzed in order to obtain constitutive relations as well as boundary conditions. It appears that the formulation leading to the establishment of boundary conditions is the first systematic approach to the problem even in the realm of molecular gases. Limitations on the results, in particular the restriction of their validity to near elastic systems are explained and shown to follow from the mesoscopic nature of granular gases.