Supersymmetric deformations of F1-NS5-branes and their exact CFT description

TL;DR

This paper explores supersymmetric deformations of F1-NS5-brane systems within an exact conformal field theory framework, revealing novel operators and their geometric interpretations, and highlighting differences from pure NS5-brane systems.

Contribution

It identifies a new class of spacetime supersymmetric operators in the exact CFT describing F1-NS5-branes, including non-chiral primaries, and interprets some as geometric or instanton deformations.

Findings

Most operators are not chiral primary with respect to N=2 superconformal algebra.

Some deformations correspond to geometric or instanton modifications of the brane system.

The CFT lacks operators for arbitrary NS5-brane geometric deformations.

Abstract

We consider certain classes of operators in the exact conformal field theory SL(2,R) x SU(2) x U(1)^4 describing strings in an AdS(3) x S(3) x T4 geometry supported by Neveu--Schwarz 3-form fluxes. This background arises in the near-horizon limit of a system of NS5-branes wrapped on a 4-torus and F1-branes smeared on the 4-torus when both types of branes are located at the same point in their common transverse space. We find a class of operators that lead to spacetime supersymmetric deformations. It is remarkable that most of these operators are not chiral primary with respect to the N=2 superconformal algebra on the wordsheet. A subset of these worldsheet conformal field theory deformations admits an interpretation either as a geometric deformation of the brane system or as a deformation of the distribution of the F1-branes, viewed as smooth instantons, inside the wrapped NS5-brane worldvolume. The 2-dimensional conformal field theory, however, seems to lack operators corresponding to arbitrary NS5-brane deformations, in contrast to pure NS5-brane systems where all geometric deformations can be accounted for by chiral primary operators.