Cosmology and large mass hierarchy in multiply warped braneworld scenario

TL;DR

This paper explores the effects of multiple warped extra dimensions on cosmological expansion, deriving conditions for brane cosmology and demonstrating consistency with observations when matter is included.

Contribution

It extends warped braneworld models to multiple extra dimensions, deriving the effective cosmological constant and conditions for realistic cosmology.

Findings

Exponential scale factor expansion is a generic feature regardless of extra dimensions.

A fine-tuning between bulk cosmological constant and brane tension is necessary.

Inclusion of bulk matter yields observationally consistent brane cosmology.

Abstract

Hubble expansion in warped braneworld model is addressed in presence of more than one warped extra dimensions. It is shown that while the expansion depends on all the moduli, an exponential nature of the expansion of the scale factor emerges as a generic feature which is independent of the number of extra dimensions. Expression for the effective brane cosmological constant in such model has been derived. It is shown that similar to the 5-dimensional Randall-Sundrum model a fine tuning between the bulk cosmological constant and brane tension is required to obtain the desired cosmological constant on the brane. The length of the extra dimensions are determined in such scenario. Finally introduing pressureless matter in the bulk an observationally consistent cosmology was obtained on the visible brane.