×

Discrete compactness for the \(p\)-version of discrete differential forms. (English) Zbl 1230.78025

Summary: We prove the discrete compactness property for a wide class of \(p\) finite element approximations of nonelliptic variational eigenvalue problems in two and three space dimensions. In a very general framework, we find sufficient conditions for the \(p\)-version of a generalized discrete compactness property, which is formulated in the setting of discrete differential forms of order \(\ell\) on a polyhedral domain in \(\mathbb R^d\) \((0<\ell<d)\). One of the main tools for the analysis is a recently introduced smoothed Poincaré lifting operator [M. Costabel and A. McIntosh, Math. Z. 265, No. 2, 297–320 (2010; Zbl 1197.35338)]. In the case \(\ell=1\), our analysis shows that several widely used families of edge finite elements satisfy the discrete compactness property in \(p\) and, hence, provide convergent solutions to the Maxwell eigenvalue problem. In particular, Nédélec elements on triangles and tetrahedra (first and second kind) and on parallelograms and parallelepipeds (first kind) are covered by our theory.

MSC:

78M10 Finite element, Galerkin and related methods applied to problems in optics and electromagnetic theory
65N25 Numerical methods for eigenvalue problems for boundary value problems involving PDEs
65N35 Spectral, collocation and related methods for boundary value problems involving PDEs

Citations:

Zbl 1197.35338