arXiv subjects

I. Roitberg

Publications and source records attributed to I. Roitberg.

2 recordsLinked to original sources

arXiv2019

Arov--Krein entropy functionals and indefinite interpolation problems

We generalize the notion of the Arov-Krein entropy functional for the case of generalized Nevanlinna functions and obtain a representation of these functionals on solutions of indefinite interpolation problems. The case of indefinite Caratheodory problem and application to Szegő limit formula for this nonclassical case are considered in greater detail.

math.FA↗

arXiv2012

Discrete Dirac system: rectangular Weyl functions, direct and inverse problems

A transfer matrix function representation of the fundamental solution of the general-type discrete Dirac system, corresponding to rectangular Schur coefficients and Weyl functions, is obtained. Connections with Szegö recurrence, Schur coefficients and structured matrices are treated. Borg-Marchenko-type uniqueness theorem is derived. Inverse problems on the interval and semiaxis are solved.

math.SP↗