Radiation reaction from soft theorems

Radiation reaction (RR) terms at the third post-Minkowskian (3PM) order have recently been found to be instrumental in restoring smooth continuity between non-relativistic, relativistic, and ultra-relativistic (including massless) regimes. Here we propose a new intriguing connection RR soft (bremsstrahlung) theorems which short-circuits more involved conventional loop computations. Although first noticed context of maximally supersymmetric theory, unitarity analyticity arguments support general validity this 3PM-order that apply, particular, Einstein's gravity its Jordan-Brans-Dicke extension. In former case find full agreement with recent result by Damour obtained through very different reasoning.