The fifth-order post-Newtonian Hamiltonian dynamics of two-body systems from an effective field theory approach

Within an effective field theory method to general relativity, we calculate the fifth-order post-Newtonian (5PN) Hamiltonian dynamics also for the tail terms, extending earlier work on the potential contributions, working in harmonic coordinates. Here we calculate independently all (local) 5PN far-zone contributions using the in-in formalism, on which we give a detailed account. The five expansion terms of the Hamiltonian in the effective one body (EOB) approach, q(82), q(63), q(44), (d) over bar (5) and an, can all be determined from the local contributions to the periastron advance K-loc,(h)( (E) over cap, j), without further assumptions on the structure of the symmetric mass ratio,., of the expansion coefficients of the scattering angle chi(k). The O(v(2)) contributions to the 5PN EOB parameters have been unknown in part before. We perform comparisons of our analytic results with the literature and also present numerical results on some observables. (C) 2022 The Author(s). Published by Elsevier B.V.