Operator Theory and Analysis: The M.A. Kaashoek Anniversary Volume Workshop in Amsterdam, November 12–14, 1997 (Operator Theory: Advances and Applications, 122)

On November 12-14, 1997 a workshop was held at the Vrije Universiteit Amsterdam on the occasion of the sixtieth birthday ofM. A. Kaashoek. The present volume contains the proceedings of this workshop. The workshop was attended by 44 participants from all over the world: partici­ pants came from Austria, Belgium, Canada, Germany, Ireland, Israel, Italy, The Netherlands, South Africa, Switzerland, Ukraine and the USA. The atmosphere at the workshop was very warm and friendly. There where 21 plenary lectures, and each lecture was followed by a lively discussion. The workshop was supported by: the Vakgroep Wiskunde of the Vrije Univer­ siteit, the department of Mathematics and Computer Science of the Vrije Univer­ siteit, the Stichting VU Computer Science & Mathematics Research Centre, the Thomas Stieltjes Institute for Mathematics, and the department of Economics of the Erasmus University Rotterdam. The organizers would like to take this opportunity to express their gratitude for the support. Without it the workshop would not have been so successful as it was. Table of Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Photograph of M. A. Kaashoek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii Curriculum Vitae of M. A. Kaashoek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv List of Publications of M. A. Kaashoek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix l. Gohberg Opening Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxi H. Bart, A. C. M. Ran and H. I. Woerdeman Personal Reminiscences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxv V. Adamyan and R. Mennicken On the Separation of Certain Spectral Components of Selfadjoint Operator Matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Conditions for the Separation of Spectral Components . . . . . . . 4 3. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . On November 12-14, 1997 a workshop was held at the Vrije Universiteit Amsterdam on the occasion of the sixtieth birthday ofM. A. Kaashoek. The present volume contains the proceedings of this workshop. The workshop was attended by 44 participants from all over the world: particiƯ pants came from Austria, Belgium, Canada, Germany, Ireland, Israel, Italy, The Netherlands, South Africa, Switzerland, Ukraine and the USA. The atmosphere at the workshop was very warm and friendly. There where 21 plenary lectures, and each lecture was followed by a lively discussion. The workshop was supported by: the Vakgroep Wiskunde of the Vrije UniverƯ siteit, the department of Mathematics and Computer Science of the Vrije UniverƯ siteit, the Stichting VU Computer Science & Mathematics Research Centre, the Thomas Stieltjes Institute for Mathematics, and the department of Economics of the Erasmus University Rotterdam. The organizers would like to take this opportunity to express their gratitude for the support. Without it the workshop would not have been so successful as it was. Table of Contents Preface ... ... ... ... ... ... v Photograph of M.A. Kaashoek ... ... ... ... xiii Curriculum Vitae of M.A. Kaashoek ... ... ... xv List of Publications of M.A. Kaashoek ... ... ... xix l. Gohberg Opening Address ... ... ... ... ... xxxi H. Bart, A.C.M. Ran and H.I. Woerdeman Personal Reminiscences ... ... ... ... . xxxv V. Adamyan and R. Mennicken On the Separation of Certain Spectral Components of Selfadjoint Operator Matrices ... ... ... . . 1 1. Introduction ... ... ... ... 1 2. Conditions for the Separation of Spectral Components ... 4 3. Example ... ... ... ... 9 References ... ... ... .. Front Matter....Pages i-xxxix On the Separation of Certain Spectral Components of Selfadjoint Operator Matrices....Pages 1-11 A Coisometric Realization for Triangular Integral Operators....Pages 13-52 Some Remarks on the Inverse Monodromy Problem for 2 x 2 Canonical Differential Systems....Pages 53-87 Interpolation and Commutant Lifting for Multipliers on Reproducing Kernel Hilbert Spaces....Pages 89-138 Sums of Idempotents and Logarithmic Residues in Matrix Algebras....Pages 139-168 Generalized Nevanlinna Functions with Polynomial Asymptotic Behaviour at Infinity and Regular Perturbations....Pages 169-189 Extensions of Matrix-valued Inner Products on Modules and the Inversion Formula for Block Toeplitz Matrices....Pages 191-227 Linear Independence of Jordan Chains....Pages 229-245 Weighted Nevanlinna-Pick Interpolation....Pages 247-274 Effects of Small Delays on Stability and Control....Pages 275-301 Generalized Bezoutian, Factorization of Rational Matrix Functions and Matrix Quadratic Equations....Pages 303-321 A Note on Factorization of Analytic Matrix Functions....Pages 323-330 Diagonalization of Certain Block Operator Matrices and Applications to Dirac Operators....Pages 331-358 Stability of Pseudospectral Factorizations....Pages 359-383 Factorization of Almost Periodic Matrix Functions of Several Variables and Toeplitz Operators....Pages 385-416 Simultaneous Similarity of Pairs of Companions to their Transposes....Pages 417-425 Back Matter....Pages 427-433 This book contains the proceedings of the international workshop organized at the Vrije Universiteit Amsterdam in November 1997 and dedicated to the sixtieth birthday of M.A. Kaashoek, one of the leading experts in operator theory and its applications. The workshop focused on areas in mathematical and functional analysis where the ideas and results of M.A. Kaashoek played an important role. The papers of this volume cover a wide range of topics centered around factorization of matrix valued functions, interpolation theory, and spectral theory. Other papers deal with canonical systems of differential equations, operators in indefinite inner product spaces, and the effect of small delays on stability and control of partial differential equations. The book starts with biographical material and a list of publications of M.A. Kaashoek. The main part consists of original research papers, which contain new interesting results. The book will be of interest to a wide range of readers in pure and applied mathematics and engineering.