Supersymmetry and Stationary Solutions in Dilaton-Axion Gravity

TL;DR

This paper introduces new stationary solutions in 4D dilaton-axion gravity, revealing their symmetries, extremal limits, and supersymmetry properties, with implications for string theory and gravitational wave dualities.

Contribution

It presents novel stationary solutions with SL(2,R) symmetry and supersymmetric properties, linking them to string theory and exact conformal field theory constructions.

Findings

Charged Taub-NUT solutions exhibit infinite throats in extremal limits.

IWP solutions admit supersymmetric Killing spinors in N=4 supergravity.

Dimensionally lifted solutions are dual to gravitational waves in string theory.

Abstract

New stationary solutions of $4$-dimensional dilaton-axion gravity are presented, which correspond to the charged Taub-NUT and Israel-Wilson-Perjes (IWP) solutions of Einstein-Maxwell theory. The charged axion-dilaton Taub-NUT solutions are shown to have a number of interesting properties: i) manifest $SL(2,R)$ symmetry, ii) an infinite throat in an extremal limit, iii) the throat limit coincides with an exact CFT construction. The IWP solutions are shown to admit supersymmetric Killing spinors, when embedded in $d=4,N=4$ supergravity. This poses a problem for the interpretation of supersymmetric rotating solutions as physical ground states. In the context of $10$-dimensional geometry, we show that dimensionally lifted versions of the IWP solutions are dual to certain gravitational waves in string theory.