Gravitational radiation from inspiralling compact objects: Spin effects to fourth Post-Newtonian order

TL;DR

This paper derives high-order spin effects in gravitational radiation from inspiralling compact binaries using effective field theory, improving the accuracy of waveform models for future gravitational wave detectors.

Contribution

It provides the next-to-next-to-leading order spin contributions to the gravitational-wave flux and orbital phase evolution in the Post-Newtonian framework.

Findings

Agreement with existing PN literature and test-body limit.

Complete spin effects in orbital phase evolution to fourth PN order.

Significant impact on gravitational-wave cycle estimates for future detectors.

Abstract

The linear- and quadratic-in-spin contributions to the binding potential and gravitational-wave flux from binary systems are derived to next-to-next-to-leading order in the Post-Newtonian (PN) expansion of general relativity, including finite-size and tail effects. The calculation is carried out through the worldline effective field theory framework. We find agreement in the overlap with the available PN literature and test-body limit. As a direct application, we complete the knowledge of spin effects in the evolution of the orbital phase for aligned-spin circular orbits to fourth PN order. We estimate the impact of the new results in the number of accumulated gravitational-wave cycles. We find they will play an important role in providing reliable physical interpretation of gravitational-wave signals from spinning binaries with future detectors such as LISA and the Einstein Telescope.