Next-to-leading tail-induced spin-orbit effects in the gravitational radiation flux of compact binaries

TL;DR

This paper extends the understanding of spin-orbit effects in gravitational wave emission from compact binaries to the next-to-leading 4PN order, enhancing the accuracy of waveform models for gravitational wave detection.

Contribution

It generalizes tail-induced spin-orbit terms to 4PN order and confirms their consistency with perturbation theory results, completing the spin-orbit phase knowledge up to this order.

Findings

Derived 4PN tail-induced spin-orbit terms for quasi-circular orbits.

Confirmed agreement with Kerr black hole perturbation theory.

Provided results to improve gravitational wave templates.

Abstract

The imprint of non-linearities in the propagation of gravitational waves --- the tail effect --- is responsible for new spin contributions to the energy flux and orbital phasing of spinning black hole binaries. The spin-orbit (linear in spin) contribution to this effect is currently known at leading post-Newtonian order, namely 3PN for maximally spinning black holes on quasi-circular orbits. In the present work, we generalize these tail-originated spin-orbit terms to the next-to-leading 4PN order. This requires in particular extending previous results on the dynamical evolution of precessing compact binaries. We show that the tails represent the only spin-orbit terms at that order for quasi-circular orbits, and we find perfect agreement with the known result for a test particle around a Kerr black hole, computed by perturbation theory. The BH-horizon absorption terms have to be added to the PN result computed here. Our work completes the knowledge of the spin-orbit effects to the phasing of compact binaries up to the 4PN order, and will allow the building of more faithful PN templates for the inspiral phase of black hole binaries, improving the capabilities of ground-based and space-based gravitational wave detectors.