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
A remark on the first eigenvalue of the Dirac operator on 4-dimensional manifolds
β Scribed by Thomas Friedrich
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- English
- Weight
- 159 KB
- Volume
- 102
- Category
- Article
- ISSN
- 0025-584X
No coin nor oath required. For personal study only.
β¦ Synopsis
By THOMAS FRIEDRICH of Berlin
(Eingegangen am 9.9. 1980) Let M* he a cony'act RIEMANNian spin inanifold with positive scalar curvature H and let R, denote its minimum. Consider the DIRAC operator D : r ( S ) + r ( S ) acting on sections of the associated spinor bundle S. If I.* is the first positive or negative eigenvalue of t,his operator, then the inequality holds. Furthermore, if R, or -A I / & R, is an eigenvalue of the 2 n -1 DIRAC operator, then M* must he an EINSTEIN space (see [I]). In the case of dimension three we proved that on S3/r the lower bound is an eigenvalue of the operator D if and only if S 3 / r is homogeneous. On the other hand, if n = 5 , we have an EINSTEIN metric of poaitive scalar curvature on the STIEFEL manifold V4,* = S0(4)/80(2) such that
π SIMILAR VOLUMES
The concept of a moment map for an action of a real Lie group by CR -diffeomorphisms on a CR -manifold M of hypersurface type is introduced. It gives rise to a natural reduction procedure in the sense that we construct a CR -structure on an associated orbit manifold M 0 for the case that the group a
We find an asymptotic expression for the first eigenvalue of the biharmonic operator on a long thin rectangle. This is done by finding lower and upper bounds which become increasingly accurate with increasing length. The lower bound is found by algebraic manipulation of the operator, and the upper b
## Abstract In this paper a number of explicit lower bounds are presented for the first Neumann eigenvalue on nonβconvex manifolds. The main idea to derive these estimates is to make a conformal change of the metric such that the manifold is convex under the new metric, which enables one to apply k