We prove a global in time existence theorem for the initial value problem for the Einstein-Boltzmann system, with positive cosmological constant and arbitrarily large initial data, in the spatially homogeneous case, in a Robertson-Walker space-time.
"Global existence of solutions for the Einstein-Boltzmann system with cosmological constant in the Robertson-Walker space-time." Commun. Math. Sci. 4 (2) 291 - 314, June 2006.