## Abstract The arguments showing non‐existence of eigensolutions to exterior‐boundary value problems associated with systems—such as the Maxwell and Lamé system—rely on showing that such solutions would have to have compact support and therefore—by a unique continuation property—cannot be non‐triv
Maxwell and Lamé eigenvalues on polyhedra
✍ Scribed by Martin Costabel; Monique Dauge
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 249 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0170-4214
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✦ Synopsis
In a convex polyhedron, a part of the Lame´eigenvalues with hard simple support boundary conditions does not depend on the Lame´coefficients and coincides with the Maxwell eigenvalues. The other eigenvalues depend linearly on a parameter s linked to the Lame´coefficients and the associated eigenmodes are the gradients of the Laplace-Dirichlet eigenfunctions. In a non-convex polyhedron, such a splitting of the spectrum disappears partly or completely, in relation with the non-H singularities of the Laplace-Dirichlet eigenfunctions. From the Maxwell equations point of view, this means that in a non-convex polyhedron, the spectrum cannot be approximated by finite element methods using H elements. Similar properties hold in polygons. We give numerical results for two L-shaped domains.
📜 SIMILAR VOLUMES
## Abstract In this paper we consider the convergence behaviour of spectral concentration intervals for unstable eigenvalues. A criterion is given to decide after the perturbation whether the unstable eigenvalue was isolated or embedded in the unperturbed case.
This paper contains some investigations concerning the asymptotic behavior of eigenvalues and eigenfunctions of elastic plates undertaken at the Institute for Advanced Study a t Princeton. The theory is based on Carleman's ingenious iden i~ his papers [l], (21. The necessary estimations of the Green