4 papers
Characteristic function of M. S. Livšic and triangular models of bounded linear operators
Vladimir K. Dubovoy, Bernd Kirstein, Conrad Mädler +1
This paper is dedicated to the introduction in a circle of ideas and methods, which are connected with the notion of characteristic function of a non-selfadjoint operator. We start…
Characteristic Function, Schur Parameters and Pseudocontinuation of Schur functions
Vladimir K. Dubovoy, Bernd Fritzsche, Bernd Kirstein +2
In [19] there is an approach to the investigation of the pseudocontinuability of Schur functions in terms of Schur parameters. In particular, there was obtained a criterion for the…
Characteristic Function, Schur Interpolation Problem and Darlington Synthesis
Sergey S. Boiko, Vladimir K. Dubovoy, Bernd Fritzsche +3
In this paper we would like to show the interrelation between the different mathematical theories concerning the Schur interpolation problem, contractions in Hilbert spaces, pseudo…
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…