Non-local string theories on AdS_3 times S^3 and stable non-supersymmetric backgrounds

TL;DR

This paper constructs and analyzes exactly marginal non-local string theories on AdS_3×S^3, demonstrating their stability and precise duality with specific deformations of 2D CFTs, including non-supersymmetric cases.

Contribution

It introduces a class of exactly marginal double-trace deformations with AdS_3 duals, providing explicit computations and demonstrating stability even without supersymmetry.

Findings

Exact agreement between string theory and CFT computations.

Stable non-supersymmetric backgrounds without destabilizing tadpoles.

Explicit analysis of effects on closed strings and D-branes.

Abstract

We exhibit a simple class of exactly marginal "double-trace" deformations of two dimensional CFTs which have AdS_3 duals, in which the deformation is given by a product of left and right-moving U(1) currents. In this special case the deformation on AdS_3 is generated by a local boundary term in three dimensions, which changes the physics also in the bulk via bulk-boundary propagators. However, the deformation is non-local in six dimensions and on the string worldsheet, like generic non-local string theories (NLSTs). Due to the simplicity of the deformation we can explicitly make computations in the non-local string theory and compare them to CFT computations, and we obtain precise agreement. We discuss the effect of the deformation on closed strings and on D-branes. The examples we analyze include a supersymmetry-breaking but exactly marginal "double-trace" deformation, which is dual to a string theory in which no destabilizing tadpoles are generated for moduli nonperturbatively in all couplings, despite the absence of supersymmetry. We explain how this cancellation works on the gravity side in string perturbation theory, and also non-perturbatively at leading order in the deformation parameter. We also discuss possible flat space limits of our construction.