D-brane gases and stabilization of extra dimensions in dilaton gravity

We consider a toy cosmological model with a gas of wrapped Dp-branes in 10-dimensional dilaton gravity compactified on a p-dimensional Ricci flat internal manifold. A consistent generalization of the low energy effective field equations in the presence of a conserved brane source coupled to dilaton is obtained. It is then shown that the compact dimensions are dynamically stabilized in string frame as a result of a balance between negative winding and positive momentum pressures. Curiously, when p = 6, i.e., when the observed space is three-dimensional, the dilaton becomes a constant and stabilization in Einstein frame is also realized. (C) 2004 Elsevier B.V. All rights reserved.