Warped brane-world compactification with Gauss-Bonnet term

TL;DR

This paper investigates the effects of Gauss-Bonnet curvature corrections in Randall-Sundrum brane-world models, deriving gravity propagators and exploring new solution branches that could address singularity issues.

Contribution

It provides a linearized gravity analysis with Gauss-Bonnet terms, deriving explicit propagators and identifying novel solution branches avoiding bulk singularities.

Findings

Gauss-Bonnet term yields a massless graviton on the brane

A new solution branch with finite Planck scale and no singularity

Explicit D-dimensional Neumann propagator derived

Abstract

In the Randall-Sundrum (RS) brane-world model a singular delta-function source is matched by the second derivative of the warp factor. So one should take possible curvature corrections in the effective action of the RS models in a Gauss-Bonnet (GB) form. We present a linearized treatment of gravity in the RS brane-world with the Gauss-Bonnet modification to Einstein gravity. We give explicit expressions for the Neumann propagator in arbitrary D dimensions and show that a bulk GB term gives, along with a tower of Kaluza-Klein modes in the bulk, a massless graviton on the brane, as in the standard RS model. Moreover, a non-trivial GB coupling can allow a new branch of solutions with finite Planck scale and no naked bulk singularity, which might be useful to avoid some of the previously known ``no--go theorems'' for RS brane-world compactifications.