Stability of inflating branes in a texture

TL;DR

This paper studies the stability of inflating branes within a textured extra dimension, showing that vacuum energy can stabilize the branes under certain conditions, unlike in flat-brane scenarios.

Contribution

It demonstrates that vacuum energy can stabilize inflating branes in a textured extra dimension, with stability depending on the symmetry-breaking scale and particle-hierarchy.

Findings

Stability depends on the symmetry-breaking scale being below a critical value.

Vacuum energy scale for stability can be significantly low.

Inflating branes are stable against gravitational perturbations in this model.

Abstract

We investigate the stability of inflating branes embedded in an O(2) texture formed in one extra dimension. The model contains two 3-branes of nonzero tension, and the extra dimension is compact. When the gravitational perturbation is applied, the vacuum energy which is responsible for inflation on the branes stabilizes the branes if the symmetry-breaking scale of the texture is smaller than some critical value. This critical value is determined by the particle-hierarchy scale between the two branes, and is smaller than the 5D Planck-mass scale. The scale of the vacuum energy can be considerably low in providing the stability. This stability story is very different from the flat-brane case which always suffers from the instability due to the gravitational perturbation.