Brane cosmology, Weyl fluid, and density perturbations
arXiv:0806.2505 · doi:10.1103/PhysRevD.78.043517
Abstract
We develop a technique to study relativistic perturbations in the generalised brane cosmological scenario, which is a generalisation of the multi-fluid cosmological perturbations to brane cosmology. The novelty of the technique lies in the inclusion of a radiative bulk which is responsible for bulk-brane energy exchange, and in turn, modifies the standard perturbative analysis to a great extent. The analysis involves a geometric fluid -- called the Weyl fluid -- whose nature and role have been studied extensively both for the empty bulk and the radiative bulk scenario. Subsequently, we find that this Weyl fluid can be a possible geometric candidate for dark matter in this generalised brane cosmological framework.
18 pages, 1 figure, accepted for publication in Phys.Rev.D