Gravitational waves from spinning compact object binaries: New post-Newtonian results

TL;DR

This paper presents advanced post-Newtonian calculations for gravitational waves from spinning compact binaries, including new high-order terms that improve waveform modeling for gravitational wave detection.

Contribution

It introduces new 3.5PN and 4PN order results for spin-orbit effects and energy flux, enhancing the accuracy of gravitational wave templates.

Findings

Derived 3.5PN order spin-orbit contributions to energy flux

Calculated 4PN tail effects in gravitational wave emission

Validated results against ADM Hamiltonian approach

Abstract

We report on recent results obtained in the post-Newtonian framework for the modelling of the gravitational waves emitted by binary systems of spinning compact objects (black holes and/or neutron stars). These new results are obtained at the spin-orbit (linear-in-spin) level and solving Einstein's field equations iteratively in harmonic coordinates as well as the multipolar post-Newtonian formalism. The dynamics of the binary was tackled at the next-to-next-to-leading order, corresponding to the 3.5 post-Newtonian (PN) order for maximally spinning objects, and the result is found to be consistent with a previously obtained reduced Hamiltonian in the ADM approach. The corresponding contribution to the energy flux emitted by the binary was obtained at the 3.5PN order, as well as the next-to-leading 4PN tail contribution to this flux, an imprint of the non-linearity in the propagation of the wave. These new terms can be used to build more accurate PN templates for the next generation of gravitational wave detectors. We give an illustrative estimate of the quantitative relevance of the new terms in the orbital phasing of the binary.