Gravitational bremsstrahlung waveform at the fourth post-Minkowskian order and the second post-Newtonian level
Gravitational bremsstrahlung waveform at the fourth post-Minkowskian order and the second post-Newtonian level
Using the Multipolar Post-Minkowskian formalism, we compute the frequency-domain waveform generated by the gravitational scattering of two nonspinning bodies at the fourth post-Minkowskian order ($O(G^4)$, or two-loop order), and at the fractional second Post-Newtonian accuracy ($O(v^4/c^4)$). The waveform is decomposed in spin-weighted spherical harmonics and the needed radiative multipoles, $U_{\ell …