We consider open manifolds which are interiors of a compact manifold with
boundary, and Riemannian metrics asymptotic to a conformally cylindrical metric
near the boundary. We show that the essential spectrum of the Laplace operator
on functions vanishes under the presence of a magnetic field which does not
define an integral relative cohomology class. It follows that the essential
spectrum is not stable by perturbation even by a compactly supported magnetic
field. We also treat magnetic operators perturbed with electric fields. In the
same context we describe the essential spectrum of the $k$-form Laplacian. This
is shown to vanish precisely when the $k$ and $k-1$ de Rham cohomology groups
of the boundary vanish. In all the cases when we have pure-point spectrum we
give Weyl-type asymptotics for the eigenvalue-counting function. In the other
cases we describe the essential spectrum.
@article{0507443,
author = {Gol\'enia, Sylvain and Moroianu, Sergiu},
title = {The spectrum of magnetic Schr\"odinger operators and $k$-form Laplacians
on conformally cusp manifolds},
journal = {arXiv},
volume = {2005},
number = {0},
year = {2005},
language = {en},
url = {http://dml.mathdoc.fr/item/0507443}
}
Golénia, Sylvain; Moroianu, Sergiu. The spectrum of magnetic Schr\"odinger operators and $k$-form Laplacians
on conformally cusp manifolds. arXiv, Tome 2005 (2005) no. 0, . http://gdmltest.u-ga.fr/item/0507443/