Showing math.FAShow all
3 papers · 1 filter
math.FA2013
On special cases of Radon - Nikodym theorem for vector and operator valued measures
S. S. Boiko, V. K. Dubovoy, A. Y. Kheifets
We present a natural and simple proof of the Radon - Nikodym theorem for measures with values in the space of bounded linear operators on a separable Hilbert space. This space is n…
math.FA2010
Description of Helson-Szegö measures in terms of the Schur parameter sequences of associated Schur functions
Vladimir K. Dubovoy, Bernd Fritzsche, Bernd Kirstein
Let mu be a probability measure on the Borelian sigma-algebra of the unit circle. Then we associate a Schur function theta in the unit disk with mu and give characterizations of th…
math.FA2009
Shift Operators Contained in Contractions, Pseudocontinuable Schur Functions and Orthogonal Systems on the Unit Circle
Vladimir K. Dubovoy, Bernd Fritzsche, Bernd Kirstein
The main aim of this paper is to establish the connection between well-known criteria for the pseudocontinuability of a non-inner Schur function Theta in the unit disk. In a canoni…