Electromagnetic Fields

The electromagnetic field quantities and their sources are represented by differential forms of different grades. In macroscopic consideration, physical materials can be represented by a set of medium parameters which define relations between the electromagnetic field quantities. The Hehl-Obukhov decomposition of the medium bidyadic can be applied to define basic classes of media. An interface is a surface which separates two media while a boundary is a mathematical concept, a surface where the region of interest ends. As is known from a medium called perfect electric conductor (PEC), a medium interface may act as a boundary. Assuming a medium which is space and time invariant, as defined by a constant bidyadic or modified bidyadic, the simplest solutions to the Maxwell equations appear to be plane waves whose sources may be ignored since they can be assumed to be outside the region under interest.