Radiation reaction in the 2.5PN waveform from inspiralling binaries in circular orbits

TL;DR

This paper analyzes the impact of radiation reaction forces on 2.5PN gravitational waveforms from inspiraling circular binaries, correcting previous inconsistencies and showing these effects are negligible at the waveform level.

Contribution

It corrects an inconsistency in prior derivations and demonstrates that radiation reaction contributions at 2.5PN are negligible for waveform modeling.

Findings

Radiation reaction effects at 2.5PN are absorbed into phase modifications at 5PN.

The paper corrects previous derivation inconsistencies.

Radiation reaction contributions are negligible in the waveform.

Abstract

In this Comment we compute the contributions of the radiation reaction force in the 2.5 post-Newtonian (PN) gravitational wave polarizations for compact binaries in circular orbits. (i) We point out and correct an inconsistency in the derivation of Arun, Blanchet, Iyer, and Qusailah. (ii) We prove that all contributions from radiation reaction in the 2.5PN waveform are actually negligible since they can be absorbed into a modification of the orbital phase at the 5PN order.