The classical double copy for Taub-NUT spacetime

TL;DR

This paper extends the classical double copy correspondence to the Taub-NUT spacetime, linking it to a dyon in gauge theory and suggesting potential extensions to curved backgrounds.

Contribution

It generalizes the classical double copy to the Taub-NUT solution with a double Kerr-Schild form, connecting it to a dyon and exploring curved background extensions.

Findings

Taub-NUT spacetime admits a double copy structure.

The single copy corresponds to a dyon with electric and magnetic charges.

Hints at extending the double copy to curved backgrounds.

Abstract

The double copy is a much-studied relationship between gauge theory and gravity amplitudes. Recently, this was generalised to an infinite family of classical solutions to Einstein's equations, namely stationary Kerr-Schild geometries. In this paper, we extend this to the Taub-NUT solution in gravity, which has a double Kerr-Schild form. The single copy of this solution is a dyon, whose electric and magnetic charges are related to the mass and NUT charge in the gravity theory. Finally, we find hints that the classical double copy extends to curved background geometries.