Introduction
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Laudation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Speech of Heinz Langer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Conference Programme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xx
List of Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiv
Bibliography of Heinz Langer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxx
Research articles
V.M. Adamyan and I.M. Tkachenko
General Solution of the Stieltjes Truncated
Matrix Moment Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Yu.M. Arlinski˘ı, S. Hassi and H.S.V. de Snoo
Q-functions of Quasi-selfadjoint Contractions . . . . . . . . . . . . . . . . . . . . . . . . 23
J. Behrndt
A Class of Abstract Boundary Value Problems with
Locally Definitizable Functions in the Boundary Condition . . . . . . . . . . . 55
P. Binding and B. ´ Curgus
Riesz Bases of Root Vectors of Indefinite Sturm-Liouville Problems
with Eigenparameter Dependent Boundary Conditions, I . . . . . . . . . . . . . 75
A. Dijksma, A. Luger and Y. Shondin
Minimal Models for N∞κ -functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
A. Fleige, S. Hassi, H.S.V. de Snoo and H. Winkler
Generalized Friedrichs Extensions Associated with
Interface Conditions for Sturm-Liouville Operators . . . . . . . . . . . . . . . . . . . 135
K.-H. F¨orster and B. Nagy
Spectral Properties of Operator Polynomials
with Nonnegative Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
B. Fritzsche, B. Kirstein and A. Lasarow
Szeg˝o Pairs of Orthogonal Rational Matrix-valued Functions
on the Unit Circle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
M. Kaltenb¨ack, H. Winkler and H. Woracek
Singularities of Generalized Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
viii Table of Contents
L.V. Mikaelyan
Orthogonal Polynomials on the Unit Circle
with Respect to a Rational Weight Function . . . . . . . . . . . . . . . . . . . . . . . . . 249
D. Popovici
Bi-dimensional Moment Problems and Regular Dilations . . . . . . . . . . . . . 257
U. Prells and P. Lancaster
Isospectral Vibrating Systems, Part 2:
Structure Preserving Transformations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
V. Strauss
A Functional Description for the Commutative WJ∗-algebras
of the D+
κ -class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
F.H. Szafraniec
On Normal Extensions of Unbounded Operators:
IV. A Matrix Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
B. Textorius
Directing Mappings in Kre˘ın Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
Survey Article
Z. Sasv´ari
The Extension Problem for Positive Definite Functions.
A Short Historical Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
