Approximation by Maxwell–Herglotz‐fields

By a general argument, it is shown that Maxwell–Herglotz‐fields are dense (with respect to the C^∞(Ω)‐topology) in the space of all solutions to Maxwell's equations in Ω. This is used to provide corresponding approximation results in global spaces (e.g. in L²‐Sobolev‐spaces H^m(Ω)) and for boundary data. Proofs are given within the framework of generalized Maxwell's equations using differential forms. Copyright © 2004 John Wiley & Sons, Ltd.