Operator Theory and Indefinite Inner Product Spaces

Research articles.- General Solution of the Stieltjes Truncated Matrix Moment Problem.- Q-functions of Quasi-selfadjoint Contractions.- A Class of Abstract Boundary Value Problems with Locally Definitizable Functions in the Boundary Condition.- Riesz Bases of Root Vectors of Indefinite Sturm-Liouville Problems with Eigenparameter Dependent Boundary Conditions, I.- Minimal Models for -functions.- Generalized Friedrichs Extensions Associated with Interface Conditions for Sturm-Liouville Operators.- Spectral Properties of Operator Polynomials with Nonnegative Coefficients.- Szeg? Pairs of Orthogonal Rational Matrix-valued Functions on the Unit Circle.- Singularities of Generalized Strings.- Orthogonal Polynomials on the Unit Circle with Respect to a Rational Weight Function.- Bi-dimensional Moment Problems and Regular Dilations.- Isospectral Vibrating Systems, Part 2: Structure Preserving Transformations.- A Functional Description for the Commutative WJ*-algebras of the D?+-class.- On Normal Extensions of Unbounded Operators: IV. A Matrix Construction.- Directing Mappings in Krein Spaces.- Survey Article.- The Extension Problem for Positive Definite Functions. A Short Historical Survey.