Dilaton-Axion hair for slowly rotating Kerr black holes

TL;DR

This paper investigates the existence of dilaton 'hair' around slowly rotating Kerr black holes, deriving it from string theory-consistent axion coupling, extending previous work on axion hair.

Contribution

It introduces a new calculation of dilaton hair for Kerr black holes considering string theory-motivated axion coupling, expanding understanding of black hole scalar hair.

Findings

Dilaton hair exists for Kerr black holes with axion coupling.

The dilaton hair is explicitly calculated for slow rotation.

Results align with low energy string theory predictions.

Abstract

Campbell et al. demonstrated the existence of axion ``hair'' for Kerr black holes due to the non-trivial Lorentz Chern-Simons term and calculated it explicitly for the case of slow rotation. Here we consider the dilaton coupling to the axion field strength, consistent with low energy string theory and calculate the dilaton ``hair'' arising from this specific axion source.