Cosmological wave maps

Abstract

We consider theories of gravity that include many coupled scalar fields with arbitrary couplings, in the geometric framework of wave maps. We examine the possibility of obtaining acceptable cosmological solutions without the inclusion of a potential term to the scalar fields. To illustrate the theory, we study two simple models and compare their solutions to those in General Relativity. We also address the issue of the conditions that must be satisfied by the wave maps for an accelerated phase of the Universe.