Correlation functions for orbifolds of the type M N/S N

Abstract

The D1–D5 system, which arises in black hole physics, gives rise to a 2-d CFT which is the low energy limit of a sigma model with target space an orbifold ( M 4) N / S N . ( M 4 is a 4-d manifold which can be T 4 or K3, and S N is the permutation group on N elements). With this motivation, we develop a method for computing correlation functions of twist operators in the bosonic 2-d CFT arising from orbifolds M N/S N , where M is an arbitrary manifold. We find intriguing relations between the CFT correlators and the gravity theory that is conjectured to be dual to the D1–D5 system.