Lifting of D1-D5-P states

TL;DR

This paper analyzes the lifting of specific BPS states in the D1-D5 conformal field theory when moving away from the orbifold point, revealing unique features of the maximally twisted sector and implications for fuzzball configurations.

Contribution

It provides a second-order computation of state lifting in the D1-D5-P system and highlights the special role of the maximally twisted sector in the CFT.

Findings

Maximally twisted sector correlators are genus one surfaces.

Lifting varies among states when deforming from the orbifold point.

Implications for studying fuzzball configurations in string theory.

Abstract

We consider states of the D1-D5 CFT where only the left-moving sector is excited. As we deform away from the orbifold point, some of these states will remain BPS while others can `lift'. We compute this lifting for a particular family of D1-D5-P states, at second order in the deformation off the orbifold point. We note that the maximally twisted sector of the CFT is special: the covering surface appearing in the correlator can only be genus one while for other sectors there is always a genus zero contribution. We use the results to argue that fuzzball configurations should be studied for the full class including both extremal and near-extremal states; many extremal configurations may be best seen as special limits of near extremal configurations.