On Multiple Eigenvalues of Selfadjoint Compact Operators
β Scribed by D. Lupo; A.M. Micheletti
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 316 KB
- Volume
- 172
- Category
- Article
- ISSN
- 0022-247X
No coin nor oath required. For personal study only.
π SIMILAR VOLUMES
to heinz langer with best wishes on the occasion of his 65th birthday For a selfadjoint operator function we study the existence of a Riesz basis consisting of eigenvectors if not for the whole space then at least for the closed linear span of all the eigenvectors.
This paper is devoted to a general min-max characterization of the eigenvalues in a gap of the essential spectrum of a self-adjoint unbounded operator. We prove an abstract theorem, then we apply it to the case of Dirac operators with a Coulomb-like potential. The result is optimal for the Coulomb p