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

We study the localization of gravity on string-like defects in codimension two. We point out that the gravity-localizing 'local cosmic string' spaceti me has an orbifold singularity at the horizon. The supergravity embedding a nd the AdS/CFT correspondence suggest ways to resolve the singularity. We f ind two resolutions of the singularity that have a semiclassical gravity de scription and study their effect on the low-energy physics on the defect. T he 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.