Inelastic Black Hole Scattering from Charged Scalar Amplitudes

TL;DR

This paper demonstrates how classical gravitational radiation from black hole scattering can be derived from gauge theory amplitudes using the double copy, potentially simplifying complex gravity calculations.

Contribution

It introduces a method to extract classical gravitational radiation from gauge theory amplitudes with scalar fields, addressing unwanted scalar forces via a ghost scalar, advancing double copy applications.

Findings

Derived gravitational radiation from gauge theory amplitudes.

Implemented a ghost scalar to remove unwanted scalar forces.

Proposed a pathway for higher-order classical gravity calculations.

Abstract

We explain how the lowest-order classical gravitational radiation produced during the inelastic scattering of two Schwarzschild black holes in General Relativity can be obtained from a tree scattering amplitude in gauge theory coupled to scalar fields. The gauge calculation is related to gravity through the double copy. We remove unwanted scalar forces which can occur in the double copy by introducing a massless scalar in the gauge theory, which is treated as a ghost in the link to gravity. We hope these methods are a step towards a direct application of the double copy at higher orders in classical perturbation theory, with the potential to greatly streamline gravity calculations for phenomenological applications.