Quasi-Thick Codimension 2 Braneworld

TL;DR

This paper investigates a codimension 2 braneworld within Einstein Gauss-Bonnet gravity, introducing the concept of quasi-thickness to incorporate brane thickness, and explores its effects on gravity and potential cosmological implications.

Contribution

It introduces the quasi-thickness formalism for codimension 2 braneworlds and analyzes its impact on gravity and cosmology within Einstein Gauss-Bonnet gravity.

Findings

Conventional Einstein gravity is recovered on the brane in the linear regime.

Nonlinear effects include corrections from brane thickness and bulk geometry.

Brane thickness may influence dark matter/energy phenomena.

Abstract

We study a codimension 2 braneworld in the Einstein Gauss-Bonnet gravity. We carefully examine the structure of possible singularities in the system which characterize the braneworld through matching conditions. Consequently, we find that the thickness of the brane can be incorporated as the distributional source, which we dub quasi-thickness. On the basis of our formalism, we analyze the linearized gravity and show the conventional Einstein gravity can be recovered on the brane. In the nonlinear regime, however, we find corrections due to the thickness and the bulk geometry. We also point out a possibility that the thickness plays a role of the dark matter/energy in the universe.