  Einstein's field equations in FRW space-times are coupled to the BGK equation
in order to derive the stress energy tensor including dissipative effects up to
second order in the thermodynamical forces. The space-time is assumed to be
matter-dominated, but in a low density regime for which a second order
(Burnett) coefficient becomes relevant. Cosmological implications of the
solutions, as well as the physical meaning of transport coefficients in an
isotropic homogeneous universe are discussed.
