2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34372Einstein'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.9 pages, submitted to CQGGeneral Relativity and Quantum CosmologyCosmological bulk viscosity, the Burnett regime, and the BGK equationtext