Branes, Waves and AdS Orbifolds

TL;DR

This paper explores the embedding of Taub-NUT and pp-wave geometries in brane setups, revealing new relationships between AdS orbifolds, spherical orbifolds, and their U-dualities, with implications for black hole physics and coupling behaviors.

Contribution

It demonstrates the U-duality between AdS orbifolds and spherical orbifolds and analyzes the coupling dynamics in these geometries, extending understanding of brane embeddings and orbifold singularities.

Findings

AdS orbifolds correspond to BTZ black holes in D1-D5 systems.

AdS orbifolds and spherical orbifolds are U-dual to each other.

AdS orbifolds exhibit a running coupling inversely related to spherical orbifolds.

Abstract

The embedding of a Taub-NUT space in the directions transverse to the world volume of branes describes branes at (spherical) orbifold singularities. Similarly, the embedding of a pp-wave in the brane world volume yields an AdS orbifold. In case of the D1-D5--brane system, the AdS3 orbifolds yields a BTZ black hole; as we will show, the same holds for D3-branes corresponding to AdS5. In addition we will show that the AdS orbifolds and the spherical orbifolds are U-dual to each other. However in contrast to spherical orbifolds the AdS orbifolds lead to a running coupling, which is in the IR inverse to the coupling of the spherical orbifold. A discussion of the general pp-wave solution in AdS space is added.