On winding branes and cosmological evolution of extra dimensions in string theory

Abstract

We consider evolution of compact extra dimensions in cosmology and try to see\nwhether wrapped branes can prevent the expansion of the internal space. Some\ndifficulties of Brandenberger and Vafa mechanism for decompactification are\npointed out. In both pure Einstein and dilaton gravities, we study cosmology of\nwinding brane gases in a continuum approximation. The energy momentum tensor is\nobtained by coupling the brane action to the gravity action and we present\nseveral exact solutions for various brane configurations. T-duality invariance\nof the solutions are established in dilaton gravity. Our results indicate that\nphenomenologically the most viable scenario can be realized when there is only\none brane wrapping over all extra dimensions.\n