Absorption of a massive scalar field by a charged black hole
We calculate the absorption cross section of a massive neutral scalar field impinging upon a Reissner-Nordstr\"om black hole. First, we derive key approximations in the high- and low-frequency regimes. Next, we develop a numerical method to compute the cross section at intermediate frequencies, and present a selection of results. Finally, we draw together our complementary approaches to give a quantitative full-spectrum description of absorption.