Properties of codimension-2 braneworlds in six-dimensional Lovelock theory

TL;DR

This paper investigates six-dimensional Lovelock gravity with codimension-2 branes, revealing solutions that exhibit self-acceleration and self-tuning, and analyzing how geometric parameters influence late-time cosmic acceleration.

Contribution

It provides new solutions for codimension-2 braneworlds in Lovelock gravity, highlighting their self-accelerating and self-tuning properties and linking geometric parameters to cosmic acceleration.

Findings

Some solutions lead to self-accelerating braneworlds.

Other solutions exhibit self-tuning properties.

The conical deficit angle relates the crossover scale to late-time acceleration.

Abstract

We consider maximally symmetric 3-branes embedded in a six-dimensional bulk spacetime with Lovelock dynamics. We study the properties of the solutions with respect to their induced curvature, their vacuum energy and their effective compactness in the extra dimensions. Some simple solutions are shown to give rise to self-accelerating braneworlds, whereas several others solutions have self-tuning properties. For the case of geometric self-acceleration we argue that the cross-over scale in between four-dimensional and higher-dimensional gravity and the scale of late-time geometric acceleration, fixed by the present horizon size, are related via the conical deficit angle of the six-dimensional bulk solution, which is a free parameter.