The Workshop on Operator Theory and Boundary Eigenvalue Problems was held at the Technical University, Vienna, Austria, July 27 to 30, 1993. It was the seventh workshop in the series of IWOTA (International Workshops on Operator Theory and Applications). The main topics at the workshop were interpolation problems and analytic matrix functions, operator theory in spaces with indefinite scalar products, boundary value problems for differential and functional-differential equations and systems theory and control. The workshop covered different aspects, starting with abstract operator theory up to contrete applications. The papers in these proceedings provide an accurate cross section of the lectures presented at the workshop. This book will be of interest to a wide group of pure and applied mathematicians.

The present book is the second of the two volume Proceedings of the Mark Krein International Conference on Operator Theory and Applications. This conference, which was dedicated to the 90th Anniversary of the prominent mathematician Mark Krein, was held in Odessa, Ukraine from 18-22 August, 1997. The conference focused on the main ideas, methods, results, and achievements of M. G. Krein. This second volume is devoted to operator theory and related topics. It opens with the bibliography of M. G. Krein and a number of survey papers about his work. The main part of the book consists of original research papers presenting the state of the art in operator theory and its applications. The first volume of these proceedings, entitled Differential Operators and related Topics, concerns the other aspects of the conference. The two volumes will be of interest to a wide-range of readership in pure and applied mathematics, physics and engineering sciences. Table of Contents Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Bibliography of Mark Grigorevich Krein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Review papers: M. G. Krein's Contributions to Prediction Theory H. Dym M. G. Krein's Contribution to the Moment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 AA Nudelman Research Papers: Solution of the Truncated Matrix Hamburger Moment Problem according to M. G. Krein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Y. M. Adamyan and I. M. Tkachenko Extreme Points of a Positive Operator Ball . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 T. Ando M-accretive Extensions of Sectorial Operators and Krein Spaces . . . . . . . . . 67 Y. M. Arlinskii A Simple Proof of the Continuous Commutant Lifting Theorem . . . . . . . . . . 83 R. Bruzual and M.

The present book is the first of the two volume Proceedings of the Mark Krein International Conference on Operator Theory and Applications. This conference, which was dedicated to the 90th Anniversary of the prominent mathematician Mark Krein, was held in Odessa, Ukraine from 18-22 August, 1997. The confer encefocused onthemain ideas, methods, results, andachievementsofM.G. Krein. This first volume is devoted to the theory of differential operators and related topics. It opens with a description of the conference, biographical material and a number of survey papers about the work of M.G. Krein. The main part of the book consists oforiginal research papers presenting the stateofthe art in the area ofdifferential operators. The second volume of these proceedings, entitled Operator Theory and related Topics, concerns the other aspects of the conference. The two volumes will be of interest to a wide-range of readership in pure and applied mathematics, physics and engineering sciences. Table of Contents Preface............................................................. v Table of Contents VII Picture of M.G. Krein Xl About the Mark Krein International Conference . Mark Grigorevich Krein (A short biography) 5 I. Gohberg The Seminar on Ship Hydrodynamics, Organized by M.G. Krein 9 v.G. Sizov Review Papers: The Works ofM.G. Krein on Eigenfunction Expansion for Selfadjoint Operators and their Applications and Development 21 Yu.M. Berezansky M.G. Krein and the Extension Theory of Symmetric Operators."

The present book is the second of the two volume Proceedings of the Mark Krein International Conference on Operator Theory and Applications. This conference, which was dedicated to the 90th Anniversary of the prominent mathematician Mark Krein, was held in Odessa, Ukraine from 18-22 August, 1997. The conference focused on the main ideas, methods, results, and achievements of M. G. Krein. This second volume is devoted to operator theory and related topics. It opens with the bibliography of M. G. Krein and a number of survey papers about his work. The main part of the book consists of original research papers presenting the state of the art in operator theory and its applications. The first volume of these proceedings, entitled Differential Operators and related Topics, concerns the other aspects of the conference. The two volumes will be of interest to a wide-range of readership in pure and applied mathematics, physics and engineering sciences. Table of Contents Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Bibliography of Mark Grigorevich Krein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Review papers: M. G. Krein's Contributions to Prediction Theory H. Dym M. G. Krein's Contribution to the Moment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 AA Nudelman Research Papers: Solution of the Truncated Matrix Hamburger Moment Problem according to M. G. Krein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Y. M. Adamyan and I. M. Tkachenko Extreme Points of a Positive Operator Ball . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 T. Ando M-accretive Extensions of Sectorial Operators and Krein Spaces . . . . . . . . . 67 Y. M. Arlinskii A Simple Proof of the Continuous Commutant Lifting Theorem . . . . . . . . . . 83 R. Bruzual and M.

Die Gmundener Seenschutztagung yom 29. September 1961, deren dort gehaltene Vortrage und anschlieflende Er6rterungen in diesem Heft teils voll- inhaltlich, teils dem Sinne nach wiedergegeben sind, hatte p r a k tis c h e un d e t his c he Z i e 1 e. Die ethlschen entsprachen dem Wunsch we iter Kreise - der fr6hlichen Feriengaste, der feinsinnigen Besucher unserer Natursch6nheiten, der eifrigen Sportfischer -, die Allgemeinheit fur den Schutz der Sch6nheit, fur die Erhaltung des naturlichen Bestandes unserer Seen, ihrer Eignung fur Bad und schonend ausgeubten Sport zu gewinnen; die praktischen Ziele bestanden in der Abwagung der M6gliehkeiten, den Zutritt zum Ufer zu gewahren, den Seen die fortschreitende Verbauung in vertretbarem Ausmafl yom Leibe zu halten, ihre technische wasserwirtschaft- liehe Verwendbarkeit zu priifen und so schliefllicheinen m6gliehst guten Ein- klang zwischen der Bewahrung naturgegebener Verhaltnisse und der In- anspruchnahme aud1 dieses Schatzes unserer Heimat durch den herandran- genden, ansprud1svollen und oft riicksichtslosen Menschen unserer Zeit her- zustellen. Das ist beim Schutz un serer Seen gewiG nicht leicht! Aber die Freunde der Natur, die Vertreter des Fremdenverkehrs, die Techniker, die Biologe- aIle diese Manner, die in Gmunden langer oder kurzer von der gebotenen Sprechm6glichkeit Gebrauch machten - waren von bestem Willen erfullt, von threm Standpunkt aus zur Er6rterung und L6sung der aufgeworfenen Fragen beizutragen. Dafur gebuhrt Ihnen der Dank der Offentlichkeit und der beiden Verbande, die diese Tagung einberufen und gestaltct haben.