Brane World Cosmologies and Statistical Properties of Gravitational Lenses

Abstract

Brane world cosmologies seem to provide an alternative explanation for the present accelerated stage of the Universe with no need to invoke either a cosmological constant or an exotic \emph{quintessence} component. In this paper we investigate statistical properties of gravitational lenses for some particular scenarios based on this large scale modification of gravity. We show that a large class of such models are compatible with the current lensing data for values of the matter density parameter $\hat{I}{\text{c◯}}_{\mathrm{m}}\le 0.94$ ($1\ddot{I}ƒ$). If one fixes $\hat{I}{\text{c◯}}_{\mathrm{m}}$ to be $\simeq 0.3$, as suggested by most of the dynamical estimates of the quantity of matter in the Universe, the predicted number of lensed quasars requires a slightly open universe with a crossover distance between the 4 and 5-dimensional gravities of the order of $1.76H_o^{-1}$.

6 pages, 3 figures, revtex