This book aims to present the theory of interpolation for rational
matrix functions as a recently matured independent mathematical subject
with its own problems, methods and applications. The authors decided to
start working on this book during the regional CBMS conference in
Lincoln, Nebraska organized by F. Gilfeather and D. Larson. The
principal lecturer, J. William Helton, presented ten lectures on
operator and systems theory and the interplay between them. The
conference was very stimulating and helped us to decide that the time
was ripe for a book on interpolation for matrix valued functions (both
rational and non-rational). When the work started and the first partial
draft of the book was ready it became clear that the topic is vast and
that the rational case by itself with its applications is already enough
material for an interesting book. In the process of writing the book,
methods for the rational case were developed and refined. As a result we
are now able to present the rational case as an independent theory.
After two years a major part of the first draft was prepared. Then a
long period of revising the original draft and introducing recently
acquired results and methods followed. There followed a period of
polishing and of 25 chapters and the appendix commuting at various times
somewhere between Williamsburg, Blacksburg, Tel Aviv, College Park and
Amsterdam (sometimes with one or two of the authors).