Early Universe Evolution in Graviton-Dilaton Models
  We present a class of graviton-dilaton models which leads to a singularity free evolution of the universe. We study the evolution of a homogeneous isotropic universe. We follow an approach which enables us to analyse the evolution and obtain its generic features even in the absence of explicit solutions, which are not possible in general. We describe the generic evolution of the universe and show, in particular, that it is singularity free in the present class of models. Such models may stand on their own as interesting models for singularity free cosmology, and may be studied accordingly. They may also arise from string theory. We discuss critically a few such possibilities. 
S. Kalyana Rama