Leading-order gravitational radiation to all spin orders

TL;DR

This paper derives the leading-order gravitational waveform and memory effect for spinning black holes at all spin orders, including next-to-leading order corrections, using on-shell amplitude methods.

Contribution

It provides a comprehensive all-spin-order calculation of gravitational radiation and memory effects, including next-to-leading order corrections, for Kerr black hole scattering.

Findings

Closed-form all-spin-order memory for anti-aligned spins.

Next-to-leading order memory computed up to sixth order in spin.

Inclusion of contact terms up to sixth order in spin.

Abstract

Starting with on-shell amplitudes compatible with the scattering of Kerr black holes, we produce the gravitational waveform and memory effect including spin at their leading post-Minkowskian orders to all orders in the spins of both scattering objects. For the memory effect, we present results at next-to-leading order as well, finding a closed form for all spin orders when the spins are anti-aligned and equal in magnitude. Considering instead generically oriented spins, we produce the next-to-leading-order memory to sixth order in spin. Compton-amplitude contact terms up to sixth order in spin are included throughout our analysis.