Anisotropy and inflation in Bianchi I brane worlds

TL;DR

This paper investigates the effects of bulk-induced anisotropic stresses on Bianchi I brane worlds, revealing persistent anisotropy, potential inflation suppression, and solutions for the mean radius in these models.

Contribution

It extends previous work by analyzing more general bulk influences, showing non-isotropization and inflation prevention due to bulk interactions in Bianchi I brane models.

Findings

Nonlocal anisotropic stresses prevent isotropization.

Bulk interactions can inhibit inflation driven by the cosmological constant.

The mean radius evolution can be fully determined within these models.

Abstract

After a more general assumption on the influence of the bulk on the brane, we extend some conclusions by Maartens et al. and Santos et al. on the asymptotic behavior of Bianchi I brane worlds. As a consequence of the nonlocal anisotropic stresses induced by the bulk, in most of our models, the brane does not isotropize and the nonlocal energy does not vanish in the limit in which the mean radius goes to infinity. We have also found the intriguing possibility that the inflation due to the cosmological constant might be prevented by the interaction with the bulk. We show that the problem for the mean radius can be completely solved in our models, which include as particular cases those in the references above.