Computational aspects of the gravitational instability problem for a   multicomponent cosmological medium
  The paper presents results for deriving closed-form analytic solutions of the non-relativistic linear perturbation equations, which govern the evolution of inhomogeneities in a homogeneous spatially flat multicomponent cosmological model. Mathematical methods to derive computable forms of the perturbations are outlined. 
H.J.Haubold and A.M.Mathai