Electromagnetostatic image theory for the PEMC sphere

The perfect electromagnetic conductor (PEMC) is a generalisation of both perfect electric-conductor (PEC) and perfect magnetic-conductor (PMC) media. Its definition, through differential-form formulation, corresponds to the simplest possible electromagnetic medium definable by a single parameter, the PEMC admittance. Its realisation for time-harmonic fields appears possible by a layer of bi-isotropic material on a PEC plane. As a basic problem, the extension of Kelvin's electrostatic image theory for the PEC sphere to that for the PEMC sphere is considered here. It is shown that, applying a suitable duality transformation, classical results for the PEC sphere can be applied to find the image solution which, for an electric point charge, involves both electric and magnetic point and line sources. The analytic result is checked by some known special cases.