Gravity localization on string-like defects in codimension two and the AdS/CFT correspondence

TL;DR

This paper investigates gravity localization on string-like defects in codimension two, exploring singularity resolutions via supergravity and AdS/CFT, and their implications for low-energy physics and potential models.

Contribution

It introduces two semiclassical resolutions of orbifold singularities in gravity-localizing backgrounds and analyzes their effects on low-energy physics and effective gravitational theories.

Findings

One resolution yields a Randall-Sundrum-like scenario.

The other results in a finite-size Kaluza-Klein compactification.

Resolutions are applicable to higher codimension backgrounds.

Abstract

We study the localization of gravity on string-like defects in codimension two. We point out that the gravity-localizing `local cosmic string' spacetime has an orbifold singularity at the horizon. The supergravity embedding and the AdS/CFT correspondence suggest ways to resolve the singularity. We find two resolutions of the singularity that have a semiclassical gravity description and study their effect on the low-energy physics on the defect. The first resolution leads, at long distances, to a codimension one Randall-Sundrum scenario. In the second case, the infrared physics is like that of a conventional finite-size Kaluza-Klein compactification, with no power-law corrections to the gravitational potential. Similar resolutions apply also in higher codimension gravity-localizing backgrounds.