Gravity on a 3-brane in 6D Bulk

TL;DR

This paper investigates gravity in six-dimensional codimension-2 brane models with tension, showing that gravity remains localized on the brane with ultra-light modes, especially when including higher curvature terms like Gauss-Bonnet.

Contribution

It demonstrates how Einstein-Hilbert and Gauss-Bonnet terms influence gravity localization in 6D brane models with tension, extending previous tensionless brane results.

Findings

Gravity is nearly localized on the brane with ultra-light modes.

Higher curvature terms can induce effective Einstein-Hilbert action on the brane.

Gravity behavior resembles tensionless brane models despite non-zero tension.

Abstract

We study gravity in codimension-2 brane world scenarios with infinite volume extra dimensions. In particular, we consider the case where the brane has non-zero tension. The extra space then is a two-dimensional ``wedge'' with a deficit angle. In such backgrounds we can effectively have the Einstein-Hilbert term on the brane at the classical level if we include higher curvature (Gauss-Bonnet) terms in the bulk. Alternatively, such a term would be generated at the quantum level if the brane matter is not conformal. We study (linearized) gravity in the presence of the Einstein-Hilbert term on the brane in such backgrounds. We find that, just as in the original codimension-2 Dvali-Gabadadze model with a tensionless brane, gravity is almost completely localized on the brane with ultra-light modes penetrating into the bulk.