Spectral estimates on 2-tori
Abstract
Description
We prove upper and lower bounds for the eigenvalues of the Dirac operator and the Laplace operator on 2-dimensional tori. In particluar we give a lower bound for the first eigenvalue of the Dirac operator for non-trivial spin structures. It is the only explicit estimate for eigenvalues of the Dirac operator known so far that uses information about the spin structure.
As a corollary we obtain lower bounds for the Willmore functional of a torus embedded into S_3.
In the final section we compare Dirac spectra for two different spin structures on an arbitrary Riemannian spin manifold.
uses pstricks package for figures
uses pstricks package for figures