Memory effect from the scattering of Taub-NUT black holes

TL;DR

This paper investigates the gravitational memory effect caused by scattering of Taub-NUT black holes using soft amplitude techniques, revealing unique features due to NUT charges and exploring related complexified gravity scenarios.

Contribution

It applies soft scattering amplitude methods to compute the memory effect of Taub-NUT black holes, highlighting novel non-linear gravitational features from NUT charges.

Findings

Computed the waveform memory effect from Taub-NUT black hole scattering.

Identified unique soft dynamics features introduced by NUT charges.

Discussed implications for celestial holography in complexified gravity.

Abstract

Taub-NUT black holes are somewhat exotic solutions to the vacuum Einstein equations, which have received limited attention in gravitational phenomenology. We use the soft behaviour of scattering amplitudes to compute the memory effect of the waveform resulting from the scattering of Kerr-Taub-NUT black holes. Due to the non-linear nature of gravity, NUT charges introduce intriguing features in the soft dynamics, which have no counterpart in the closely related setting of monopole charges in electromagnetism. In addition to this potentially realistic problem, we also comment on the purely academic problem in complexified gravity of the scattering of self-dual Taub-NUT black holes, which have been discussed recently in the context of celestial holography.