Generalized Compactification and Assisted Dynamics of Multi--Scalar Field Cosmologies

Abstract

Cosmological models arising from a generalized compactification of Einstein gravity are derived. It is shown that a redefinition of the moduli fields reduces the system to a set of massless fields and a single field with a single exponential potential, independent of the background spacetime. This solution is the unique late--time attractor for an arbitrary spacetime dimensionality. We find that if the number of dimensions is greater than or equal to seven, the scalar fields dominate a relativistic fluid and therefore constitute a potential `moduli' problem.

Comments: 4 pages, latex file. Version to appear in Phys. Rev. D. Argument showing that the solution found is the unique late time attractor added, reorganised contents and new title