Tel Aviv University
 
Hello everyone,
 
The next colloquium talk will be held on Monday, 5/12/2011, 12:15, Schreiber
006, Tel Aviv University. The speaker is
 
     Simone Warzel (Princeton and TU Munich)
 
and the title of her talk is
 
     Resonances and absolutely continuous spectra of random operators
on tree graphs
 
The abstract is given below. Tea and coffee at 12:00, same room.
 
Hope to see you there. For information about future colloqiua, see
 <http://www.math.tau.ac.il/~klartagb/colloq_2011.html>
 
You are all welcome to suggest colloquium speakers, especially for the end
of January and for the second semester.
 
Yours,
Bo'az
 
--------------
 
Abstract: Motivated by the quest for a theory of quantum transport in
disordered media, in 1958 P.W. Anderson came up with a model for a quantum
particle in a random energy landscape. Among its interesting features is a
conjectured sharp transition from a regime of localized eigenstates to one
of diffusive transport. Until today it remains a mathematical challenge to
establish these features in the framework of random Schroedinger operators.
 
In this talk, I will describe recent progress in the understanding of the
spectral and dynamical properties of such operators in case the underlying
configuration space is a tree graph. Among the surprising phenomena which we
discover is that even at weak disorder the regime of absolutely continuous
states extends well beyond the one of the graph Laplacian. As will be
explained in the lecture, the mathematical mechanism for the appearance of
absolutely continuous states in this non-perturbative regime are
disorder-induced resonances.
 
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Technion Math Net-2 (TECHMATH2)
Editor: Michael Cwikel   <techm@math.technion.ac.il> 
Announcement from:  <klartagb@post.tau.ac.il>