Radial fall: The gravitational waveform up to the second-and-half post-Newtonian order
Phys. Rev. D 114, 064068 – Published 21 September, 2026
DOI: https://doi.org/10.1103/6x3q-pdz4
Abstract
We consider an application of the multipolar post-Minkowskian formalism to the case of a two-body system in radial fall. We compute, within the post-Newtonian approximation, the associated gravitational waveform reaching the 2.5 post-Newtonian accuracy level. At this level the presence of a radiation-reaction force manifests, modifying the fall with a corresponding bremsstrahlung radiation. We evaluate then all emissions: energy, angular momentum (vanishing identically), and linear momentum. We also evaluate the (nonlocal) inertial forces contributions appearing (at the next PN order, 4.5PN) in the center-of-mass due to the losses paving the way for future more accurate computations.
