Hello, Im looking for some time dependent exact solution of Einsteins eqs. If Im right (if not please correct me) the easiest one is Robertson - Walker cosmological solution for homogeneous and isotropic universe (this use Oppenheimer and Snyder for collapse). I cant find another in common literature. Is it some "easyone", not necessary physicaly relevant, solution? Or some list or something like that? Im really curious how such solution in metric form (lenght element) looks like. Thank you for replies.