Equivalent layers of surface charge, current sheet, and polarization in the eigenfunction expansions of Green´s functions in electromagnetic theory

The discontinuous behavior of the eigenfunction expansion of various Green´s functions commonly used in electromagnetic theory is discussed with the aid of equivalent layers of surface charge, current sheet, and surface polarization. Green´s function pertaining to the potential function in electrostatics is discussed first, followed by a detailed analysis of an eigenfunction representation of a typical dyadic Green´s function for time-varying harmonic fields.