Ehlers--Harrison--Type Transformations in Dilaton--Axion Gravity

TL;DR

This paper identifies a ten-parameter internal symmetry group in a specific four-dimensional gravity theory with dilaton and axion fields, enabling the derivation of new rotating dyon solutions.

Contribution

It uncovers a new symmetry group combining duality and Harrison-type transformations, and applies it to generate novel rotating dyon solutions in dilaton-axion gravity.

Findings

Discovered a ten-parametric internal symmetry group.

Derived a seven-parametric family of rotating dilaton-axion Taub-NUT dyons.

Showed the symmetry includes dilaton-axion duality and Harrison-type transformations.

Abstract

The ten--parametric internal symmetry group is found in the $D=4$ Einstein--Maxwell--Dilaton--Axion theory restricted to space--times admitting a Killing vector field. The group includes dilaton--axion $SL(2,R)$ duality and Harrison--type transformations which are similar to some target--space duality boosts, but act on a different set of variables. New symmetry is used to derive a seven--parametric family of rotating dilaton--axion Taub--NUT dyons.