Paper detail

Bouncing and cyclic universes from brane models

We consider a D3-brane as boundary of a five dimensional charged anti de Sitter black hole. We show that the charge of the black hole induces a regular cosmological evolution for the scale factor of the brane, with a smooth transition between a contracting and an eventual expanding phase. Simple analytical solutions can be obtained in the case of a vanishing effective cosmological constant on the brane. A nonvanishing cosmological constant, or the inclusion of radiation on the brane, does not spoil the regularity of these solutions at small radii, and observational constraints such as the ones from primordial nucleosynthesis can be easily met. Fluctuations of brane fields remain in the linear regime provided the minimal size of the scale factor is sufficiently large. We conclude with an analysis of the Cardy-Verlinde formula in this set up.