Gravitational bremsstrahlung from spinning binaries in the post-Minkowskian expansion

TL;DR

This paper calculates gravitational wave momentum radiation from spinning binary scattering using a novel effective field theory approach, revealing that spins enable momentum loss in all spatial directions, extending previous nonspinning results.

Contribution

It introduces a new method combining Routhian formalism and loop integrals to compute gravitational radiation from spinning binaries at leading order in G and quadratic in spins.

Findings

Spinning binaries radiate momentum in all three spatial directions.

The energy radiation matches post-Newtonian calculations.

Spins significantly influence the directionality of gravitational wave momentum loss.

Abstract

We present a novel calculation of the four-momentum that is radiated into gravitational waves during the scattering of two arbitrarily spinning bodies. Our result, which is accurate to leading order in $G$, to quadratic order in the spins, and to all orders in the velocity, is derived by using a Routhian-based worldline effective field theory formalism in concert with a battery of analytic techniques for evaluating loop integrals. While nonspinning binaries radiate momentum only along the direction of their relative velocity, we show that the inclusion of spins generically allows for momentum loss in all three spatial directions. We also verify that our expression for the radiated energy agrees with the overlapping terms from state-of-the-art calculations in post-Newtonian theory.