Representation of arbitrary charge–current densities by polarization and magnetization fields

Abstract

It is shown that any electromagnetic charge–current distribution may be expressed in terms of polarization and magnetization fields, plus a static charge density of one sign if the total charge q is nonzero, and that the standard Maxwell equations reduce, in general, to the conventional form used for material media plus a static Gauss law if q≠0. Examples considered include a capacitor, a point charge and an oscillating point electric dipole in arbitrary motion, and lumpy media composed of oscillating point electric dipoles or other particles.