We complete the calculation of conservative two-body scattering dynamics at fourth post-Minkowskian order, i.e. O(G4) and all orders in velocity, including radiative contributions corresponding to the tail effect in general relativity. As in previous calculations, we harness powerful tools from the modern scattering amplitudes program including generalized unitarity, the double copy, and advanced multiloop integration methods, in combination with effective field theory. The classical amplitude involves complete elliptic integrals, and polylogarithms with up to transcendental weight two. Using the amplitude-action relation, we obtain the radial action directly from the amplitude, and match the known overlapping terms in the post-Newtonian expansion.
@article{arxiv.2112.10750,
title = {Scattering Amplitudes, the Tail Effect, and Conservative Binary Dynamics at $O(G^4)$},
author = {Zvi Bern and Julio Parra-Martinez and Radu Roiban and Michael S. Ruf and Chia-Hsien Shen and Mikhail P. Solon and Mao Zeng},
journal= {arXiv preprint arXiv:2112.10750},
year = {2022}
}