A. Fedotov and F. Klopp
Coexistence of different spectral types for almost periodic 
Schr{\"o}dinger equations in dimension one
(261K, gzipped Postscript)

ABSTRACT.  This paper is an enhanced version of a talk given at the conference 
QMath 7 that was held in Prague (Czech Republic), 22-26 June 1998. 
It is devoted to the study of almost periodic Schr{\"o}dinger equations 
in dimension 1. The main result is the proof of the coexistence of 
absolutely continuous and singular spectrum for such equations. We 
also give a criterion for the existence of absolutely continuous and 
singular spectrum.