On Hybrid (Topologically) Massive Supergravity in Three Dimensions

TL;DR

This paper explores a class of hybrid topologically massive supergravity theories in three dimensions, analyzing their vacuum stability, critical points, and exact BPS solutions, including a string solution dual to a 2D CFT.

Contribution

It introduces a new parameter regime where the auxiliary field remains non-dynamical and provides a detailed linearized analysis, criticality conditions, and exact BPS solutions.

Findings

Identifies parameter choices for ghost-free Minkowski vacuum.

Finds critical points where one graviton becomes pure gauge.

Constructs a BPS string solution dual to a 2D CFT.

Abstract

A class of hybrid (topologically) massive off-shell supergravities coupled to an on-shell matter scalar multiplet was recently constructed. The auxiliary field in the off-shell multiplet is dynamical for generic values of the eight parameters. We find that by choosing the parameters appropriately, it remains non-dynamical. We perform linearized analysis around the supersymmetric AdS3 vacuum and its Minkowski limit. The ghost-free condition for the Minkowski vacuum is explored. For the AdS3 vacuum, we obtain the criticality condition and find that at the critical points, one of the two massive gravitons becomes pure gauge and decouples from the bulk physics, whilst the other has positive energy. We demonstrate that the mass of the BTZ black hole is non-negative at the critical points. We also investigate general BPS solutions. For certain parameter choices, we obtain exact solutions. In particular, we present the BPS string (domain-wall) solution that is dual to certain two-dimensional quantum field theory with an ultra-violet conformal fixed point.