3 research outputs found
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.Comment: 13 pages, final versio