Gravitational radiation reaction and balance equations to post-Newtonian order

TL;DR

This paper extends the analysis of gravitational radiation reaction forces and balance equations to 1.5PN order, providing detailed corrections and confirming their validity for general systems and binary systems.

Contribution

It derives 1PN relativistic corrections to the radiation reaction potential and confirms the balance equations at 1.5PN order for general systems.

Findings

Derived 1PN corrections to radiation reaction potential.

Confirmed balance equations at 1.5PN order.

Validated results for binary systems at 3.5PN approximation.

Abstract

Gravitational radiation reaction forces and balance equations for energy and momenta are investigated to 3/2 post-Newtonian (1.5PN) order beyond the quadrupole approximation, corresponding to the 4PN order in the equations of motion of an isolated system. By matching a post-Newtonian solution for the gravitational field inside the system to a post-Minkowskian solution (obtained in a previous work) for the gravitational field exterior to the system, we determine the 1PN relativistic corrections to the ``Newtonian" radiation reaction potential of Burke and Thorne. The 1PN reaction potential involves both scalar and vectorial components, with the scalar component depending on the mass-type quadrupole and octupole moments of the system, and the vectorial component depending in particular on the current-type quadrupole moment. In the case of binary systems, the 1PN radiation reaction potential has been shown to yield consistent results for the 3.5PN approximation in the binary's equations of motion. Adding up the effects of tails, the radiation reaction is then written to 1.5PN order. In this paper, we establish the validity to 1.5PN order, for general systems, of the balance equations relating the losses of energy, linear momentum, and angular momentum in the system to the corresponding fluxes in the radiation field far from the system.