New perturbative solutions of the Kerr-Newman dilatonic black hole field equations

TL;DR

This paper presents new perturbative solutions for Kerr-Newman dilaton black holes that do not assume slow rotation, revealing a novel symmetry and calculating the black hole's gyromagnetic ratio.

Contribution

It introduces a new perturbative approach for Kerr-Newman dilaton black holes without slow rotation assumptions and uncovers a mirror symmetry in the theory.

Findings

Discovered a new conjugation symmetry mapping small to strong coupling sectors.

Derived perturbative solutions for Kerr-Newman dilaton black holes.

Calculated the gyromagnetic ratio of the black hole.

Abstract

This work describes new perturbative solutions to the classical, four-dimensional Kerr--Newman dilaton black hole field equations. Our solutions do not require the black hole to be slowly rotating. The unperturbed solution is taken to be the ordinary Kerr solution, and the perturbation parameter is effectively the square of the charge-to-mass ratio $(Q/M)^2$ of the Kerr--Newman black hole. We have uncovered a new, exact conjugation (mirror) symmetry for the theory, which maps the small coupling sector to the strong coupling sector ($\phi \to -\phi$). We also calculate the gyromagnetic ratio of the black hole.