Electromagnetic wave scattering by spheroidal objects using a method of spin-weighted harmonics

We describe a technique for calculating wave propagation adapted from the study of black hole perturbations in general relativity, and illustrate its use by treating the scattering of plane electromagnetic radiation by perfectly conducting oblate spheroids. The technique employs expansions in terms of orthogonal functions called spin-weighted spheroidal harmonics. The advantages of the technique are that it suppresses the vectorial nature of the problem and allows for simple application of boundary conditions. A specialization to the spherical case is made in order to compare explicit analytical expressions to well-known results.