Radiation-reaction and angular momentum loss at the second Post-Minkowskian order

We compute the variation of the Fokker-Wheeler-Feynman total linear and angular momentum of a gravitationally interacting binary system under the second post-Minkowskian retarded dynamics. The resulting $O(G^2)$ equations-of-motion-based, total change in the system’s angular momentum is found to agree with existing computations that assumed balance with angular momentum fluxes in the radiation zone.