Thursday, 27th April 2006, 4:00 pm
Mathematics Building, Lecture Hall 2
Yoram Last
(Hebrew University)
"A New Proof of Poltoratskii's Theorem"
Abstract:
Poltoratskii's theorem (first proved by Poltoratskii in 1993)
says that the ratio of Borel-Stieltjes transforms of two
complex-valued Borel measures on the real line, in the limit
of approaching the real line, converges to the corresponding
Radon-Nikodym derivative almost everywhere with respect to their
singular (w.r.t. Lebesgue measure) parts. The talk will discuss
some consequences of this theorem and present a surprisingly
simple proof of it using the spectral theorem and rank-one
perturbations of self-adjoint operators. This is joint work
with V. Jaksic.
Light refreshments will be served in the faculty lounge at 3:30.
