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arXiv · 2604.01699

Radial fall: the gravitational waveform up to the second-and-half Post-Newtonian order

Donato Bini·Giorgio Di Russo
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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.

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Donato Bini, Giorgio Di Russo. 2026-04-02. Radial fall: the gravitational waveform up to the second-and-half Post-Newtonian order. https://arxiv.org/abs/2604.01699

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