A rationale for 'edge-elements' in 3-D fields computations

A justification for the use of finite elements with edge-attached degrees of freedom (edge-elements) is sought in some mathematical structures that underlie eddy-current theory. An introduction to so-called mixed methods in magnetostatics is given, and two dual methods for eddy-current computations, both making use of edge elements, are shown to derive from these considerations.< >