Dynamics of Robertson-Walker spacetimes with diffusion
  We study the dynamics of spatially homogeneous and isotropic spacetimes
containing a fluid undergoing microscopic velocity diffusion in a cosmological
scalar field. After deriving a few exact solutions of the equations, we
continue by analyzing the qualitative behavior of general solutions. To this
purpose we recast the equations in the form of a two dimensional dynamical
system and perform a global analysis of the flow. Among the admissible
behaviors, we find solutions that are asymptotically de-Sitter both in the past
and future time direction and which undergo accelerated expansion at all times.
