On braneworld cosmologies from six dimensions, and absence thereof

TL;DR

This paper investigates six-dimensional braneworld models with Einstein-Gauss-Bonnet gravity and finds that axially symmetric bulk configurations do not admit isotropic cosmological solutions, highlighting limitations of such models.

Contribution

It demonstrates the absence of isotropic cosmological solutions in six-dimensional Einstein-Gauss-Bonnet braneworlds with axial symmetry.

Findings

No isotropic braneworld cosmologies exist in the considered model.

The Gauss-Bonnet term is essential for non-trivial brane matter.

Axial symmetry constrains the solutions, preventing isotropy.

Abstract

We consider (thin) braneworlds with conical singularities in six-dimensional Einstein-Gauss-Bonnet gravity with a bulk cosmological constant. The Gauss-Bonnet term is necessary in six dimensions for including non-trivial brane matter. We show that this model for axially symmetric bulks does not possess isotropic braneworld cosmological solutions.