On Lie Point Symmetries of Einstein's equations for the Friedmann-Roberstson-Walker Cosmology

Abstract

We study the Lie point symmetries of Einstein's equations for the Friedmann-Roberstson-Walker Cosmology. They form either a two - dimensional or a three - dimensional solvable group depending on the form of the self interacting potential. Using the invariants of the group we reduce the second order system of differential equations into a first order system. Writing the action in terms of the proper time we study the point symmetries and the variational symmetries of the resulting equations.