Far-Zone Gravitational Interactions at the Sixth Post-Newtonian Order
We compute the nonlinear far-zone dynamics of compact binaries at the sixth post-Newtonian (6PN) order in the effective field theory of general relativity. We derive the complete $\mathcal{O}(G^2)$ far-zone action of a generic multipolar source in both the causal and the conservative prescriptions. Besides the known ta...