Low-frequency-limit conversion cross sections for charged black holes

Because gravitational and electromagnetic fields are coupled in the presence of a charged black hole, such a black hole possesses a cross section for the conversion of gravitational to electromagnetic radiation and vice versa. In this paper, this phenomenon is used to consider the conversion scattering of a "test charge" (which is modeled as small mass, charged black hole) in a classical gravitational or electromagnetic radiation field. The total cross section for the conversion between these types of radiation is numerically calculated to be ${\sigma }_{\mathrm{totconv}}=1.33\mathrm{}{e}^2$. Differential cross sections for incident plane or circularly polarized radiation are also exhibited.