Peter Kuchment, Sergei Levendorski
On absolute continuity of spectra of periodic elliptic operators
(19K, LaTeX)
ABSTRACT. The paper contains a brief description of a simplified version of A.
Sobolev's proof of absolute continuity of spectra of periodic
magnetic Schr\"{o}dinger operators. This approach is applicable to all
periodic elliptic operators known to be of interest for math physics
(including Maxwell), and in all these cases leads to the same model
problem of complex analysis. The full account of this approach will
be provided elsewhere.