Solutions for Neutral for Axi-Dilaton Gravity in 4-Dimensions

TL;DR

This paper explores a class of 4D axi-dilaton gravity solutions, utilizing SL(2,R) symmetry to generate electromagnetically neutral configurations with scalar charges, extending insights from Brans-Dicke theory.

Contribution

It introduces a method to construct neutral solutions in axi-dilaton gravity using symmetry transformations, linking string-inspired models to scalar-tensor theories.

Findings

Constructed a family of neutral solutions with scalar charges.

Demonstrated the use of SL(2,R) symmetry in solution generation.

Discussed solutions for negative coupling parameters.

Abstract

We examine a 1 parameter class of actions describing the gravitational interaction between a pair of scalar fields and Einsteinian gravitation. When the parameter is positive the theory corresponds to an axi-dilatonic sector of low energy string theory. We exploit an SL(2,R) symmetry of the theory to construct a family of electromagnetically neutral solutions with non-zero axion and dilaton charge from solutions of the Brans-Dicke theory. We also comment on solutions to the theory with negative coupling parameter.