Penrose limits in massive type-IIA AdS$_3$ background

TL;DR

This paper explores Penrose limits of a massive type IIA supergravity background obtained via non-Abelian T-duality of an AdS3 x S3 x T4 space, revealing a supersymmetric pp-wave geometry with potential gauge theory duals.

Contribution

It demonstrates that certain null geodesics in the non-Abelian T-dual background lead to supersymmetric pp-wave geometries, expanding understanding of dualities in string theory backgrounds.

Findings

Identified a null geodesic leading to a pp-wave in the dual background.

The resulting pp-wave preserves sixteen supercharges.

Discussed potential gauge theory duals of the pp-wave geometry.

Abstract

In this paper we consider the non-Abelian T-dual geometry of the type $IIB$ supergravity theory on $AdS_3\times S^3\times T^4$ background along a convenient $SU(2)$ subgroup of the $SO(4)$ R-symmetry. We examine various null geodesics of the resulting massive type $IIA$ supergravity theory and investigate the Penrose limits along these geodesics. We find that one of the resulting backgrounds admits pp-wave geometry in the neighbourhood of a suitable null geodesic. We carry out the supersymmetry analysis of the resulting pp-wave geometry and observe that it preserves sixteen supercharges. Further we comment on the possible gauge theory dual of the resulting pp-wave background.