Electromagnetic radiation reaction and energy extraction from black holes: The tail term cannot be ignored
1 : CENTRA - IST
2 : CAMSDG/IST
We study electromagnetic radiation reaction in curved space and the dynamics of radiating charged particles (Phys. Rev. D 107, 064046 (2023)). The equation of motion for such particles is the DeWitt-Brehme equation, and it contains a particularly complicated, non-local, tail term. It has been claimed that the tail term can be neglected in certain magnetized black hole spacetimes, and that radiation reaction may then lead to energy extraction (``orbital widening") in the absence of an ergoregion. We show that such claims are incorrect, at least in the Newtonian limit: the tail term can never be neglected consistently in the relevant scenarios, and when it is included the reported energy extraction no longer occurs.