Randall-Sundrum Model in the Presence of a Brane Bulk Viscosity
Abstract
Description
The presence of a bulk viscosity for the cosmic fluid on a single Randall-Sundrum brane is considered. The spatial curvature is assumed to be zero. The five-dimensional Friedmann equation is derived, together with the energy conservation equation for the viscous fluid. These governing equations are solved for some special cases: (i) in the low-energy limit when the matter energy density is small compared with brane tension; (ii) for a matter-dominated universe, and (iii) for a radiation-dominated universe. Rough numerical estimates, for the extreme case when the universe is at its Planck time, indicate that the viscous effect can be significant.
18 pages, RevTeX4, no figures. Discussion in Sec. III expanded; new references. To appear in Phys. Rev. D
18 pages, RevTeX4, no figures. Discussion in Sec. III expanded; new references. To appear in Phys. Rev. D