A Generalized Functions
A.1 INTRODUCTION
When solving certain electromagnetic radiation and scattering problems, it is common practice to simplify or idealize the problems by examining a limiting case of an actual source distribution. An example encountered early in the study of electromagnetic fields is the concept of a surface current—one that exists only on a surface (of infinitesimal thickness). In similar fashion, we may idealize the current on a wire into that of a line source—current on a wire of zero radius. In these and certain other cases, the volume current density must become infinite on a certain set of points, while the total current (the integral of this density) through a transverse surface remains finite.
Of interest ...
