The  Weizmann  Institute  of  Science
                  Faculty of Mathematics and Computer Science
                                 Guest Seminar
                    Seminar Room, Room 261, Ziskind Building
                           on Thursday, July 21, 2011
                                    at 15:00
                            Please note unusual time
                                  Mira Shamis
                          Institute for Advanced Study
                                 will speak on
                    Some connections between almost periodic
     and periodic discrete Schroedinger operators with analytic potentials
We study discrete Schroedinger operators with analytic potentials. In
particular, we are interested in the connection between the absolutely
continuous spectrum in the almost periodic case and the spectra in the periodic
case. We prove a weak form of a precise conjecture (due to Y. Last) relating
the two.
We also bound the measure of the spectrum in the periodic case in terms of the
Lyapunov exponent in the almost periodic case.
In the proofs, we use a partial generalization of Chambers' formula. Time
perimitting, we shall show an additional application of this generalization: a
proof of Herman's lower bound for the Lyapunov exponent.
Technion Math Net-2 (TECHMATH2)
Editor: Michael Cwikel   <> 
Announcement from: Diana Mandelik   <>