Operator Theory: Advances and Applications VoI. 135 Editor: 1. Gohberg Editorial Oftice: School of Mathematical Sciences Tel Aviv University Ramat Aviv, Israel Ed itorial Board: P. Lancaster (Calgary) J. Arazy (Haifa) L.E. Lerer (Haifa) A. Atzmon (Tel Aviv) B. Mityagin (Columbus) J. A. BaII (Blacksburg) V. V. Peller (Manhattan, Kansas) A. Ben-Artzi (Tel Aviv) J. D. Pincus (Stony Brook) H. Bercovici (Bloomington) M. Rosenblum (Charlottesville) A. Battcher (Chemnitz) J. Rovnyak (Charlottesville) K. Clancey (Athens, USA) D. E. Sarason (Berkeley) L. A. Coburn (Buftalo) H. Upmeier (Marburg) K. R. Davidson (Waterloo, Ontario) S. M. Verduyn Lunei (Amsterdam) R. G. Douglas (Stony Brook) D. Voiculescu (Berkeley) H. Dym (Rehovot) H. Widom (Santa Cruz) A. Dynin (Columbus) D. Xia (Nashville) P. A. Fillmore (Halifax) D. Yafaev (Ren nes) P. A. Fuhrmann (Beer Sheva) S. Goldberg (College Park) Honorary and Advisory B. Gramsch (Mainz) Editorial Board: G. Heinig (Chemnitz) C. Foias (Bloomington) J. A. Helton (La Jolla) P. R. Halmos (Santa Clara) M.A. Kaashoek (Amsterdam) T. Kailath (Stanford) H.G. Kaper (Argonne) P. D. Lax (New York) S.T. Kuroda (Tokyo) M. S. Livsic (Beer Sheva) Toeplitz Matrices and Singular Integral Equations The Bernd Silbermann Anniversary Volume Albrecht Bottcher Israel Gohberg Peter Junghanns Editors Springer Basel AG Editors: Albrecht Btittcher Peler Junghanns Faculty of Mathematics Faculty of Mathematics Technical University Chemnitz Technical University Chemnitz 09107 Chemnitz 09107 Chemnitz Germany Germany e-mail: [email protected] e-mail: [email protected] Israel Gohberg School of Mathematical Sciences Raymond and Beverly Sack1er Faculty of Exact Sciences Tel Aviv University Ramat Aviv 69978 Israel e-mail: [email protected] 2000 Mathematics Subject C!assification 47-06; 47A56, 47B35, 47B48, 47N20, 47N70 A CIP catalogue record for this book is available from the Library of Congress, Washington D.C., USA Deutsche Bibliothek Cataloging-in-Publication Data Toeplitz matrices and singular integral equations : the Bemd Silbermann anniversary volume / Albrecht Btittcher ... ed. - Basel ; Boston; Berlin: Birkhliuser, 2002 (Operator theory ; VoI. 135) ISBN 978-3-0348-9471-5 ISBN 978-3-0348-8199-9 (eBook) DOI 10.1007/978-3-0348-8199-9 This work is subject to copyright. AII rights are reserved, whether the whole or part of the material is concemed, specifically the rights of translation, reprinting, re-use of iIIustrations, recitation, broadcasting, reproduction on microfi1~ or in other ways, and storage in data banks. For any kind of use permission of the copyright owner must be obtained. © 2002 Springer Basel AG Originally published by Birkhăuser Verlag Basel, Switzerland in 2002 Printed on acid-free paper produced from chlorine-free pulp. TCF 00 Cover design: Heinz Hiltbrunner, Basel www.birkhauser-science.com 987654321 Contents Editorial Preface .......................................................... vii Portrait of Bernd Silbermann ............................................. viii A. Bottcher Essay on Bernd Silbermann .......................................... 1 Publications of Bernd Silbermann ......................................... 13 J.A. Ball, L. Rodman and I.M. Spitkovsky Toeplitz Corona Problem for Algebras of Almost Periodic Functions ........................................... 25 H. Bart, T. Ehrhardt and B. Silbermann Sums of Idempotents in the Banach Algebra Generated by the Compact Operators and the Identity ............... 39 E.L. Basor and T. Ehrhardt Asymptotic Formulas for the Determinants of Symmetric Toeplitz plus Hankel Matrices............................ 61 A. Bottcher On the Determinant Formulas by Borodin, Okounkov, Baik, Deift and Rains................................................ 91 A. Bottcher, S. Grudsky and A . Kozak On the Distance of a Large Toeplitz Band Matrix to the Nearest Singular Matrix ...................................... 101 L.P. Castro, R. Duduchava and F.-G. Speck Singular Integral Equations on Piecewise Smooth Curves in Spaces of Smooth Functions ....................................... 107 V.D. Didenko and B. Silbermann Spline Approximation Methods for the Biharmonic Dirichlet Problem on Non-smooth Domains.......................... 145 B. Fritzsche, B. Kirstein and A. Lasarow On Rank Invariance of Schwarz-Pick-Potapov Block Matrices of Matrix-valued CaratModory Functions............................ 161 I. Gohberg, M.A. Kaashoek and F. van Schagen Finite Section Method for Linear Ordinary Differential Equations Revisited ..................................... 183 VI Contents G. Heinig and K. Rost Fast Algorithms for Skewsymmetric Toeplitz Matrices ............... 193 P. Junghanns, K. Muller and K. Rost On Collocation Methods for Nonlinear Cauchy Singular Integral Equations ................................................... 209 Yu. Karlovich and B. Silbermann Local method for nonlocal operators on Banach spaces 235 G. Mastroianni and G. M onegato Numerical Solution of Mellin Type Equations via Wiener-Hopf Equations.......................................... 249 A. Pietsch A 1-parameter Scale of Closed Ideals Formed by Strictly Singular Operators ....................................... 261 V.S. Rabinovich and S. Roch Local Theory of the Fredholmness of Band-dominated Operators with Slowly Oscillating Coefficients ....................... 267 S. Serra-Capizzano More Inequalities and Asymptotics for Matrix Valued Linear Positive Operators: the Noncommutative Case 293 H. Widom Toeplitz Determinants, Random Matrices and Random Permutations .......................................... 317 Editorial Preface This volume is dedicated to Bernd Silbermann on the oc casion of his sixtieth birthday. It consists of selected papers devoted to the inexhaustible and ever-young fields of Toeplitz matrices and singular integral equations, and thus to areas Bernd Silbermann has been enriching by fundamental con tributions for the last three decades. Most authors of this volume participated in the conference organized and sponsored by the Department of Mathematics (under the deans Dieter Happel and Jiirgen vom Scheidt) of the Chemnitz University of Technology in honor of Bernd Silbermann in Pobershau, April 8-12, 2001. The majority of the papers presented here are based on the talks given on that conference. We thank all contributors for their enthusiasm when preparing the articles for this volume. BERND SILBERMANN Operator Theory: Advances and Applications, Vol. 135, 1-12 © 2002 Birkhiiuser Verlag Basel/Switzerland Essay on Bernd Silbermann Albrecht Bottcher Bernd Silbermann was born on 6 April 1941 in Langhennersdorf, a village in Sax ony. His parents were farmers. To this day, he is proud of his ability to drive a tractor. He went to school in Langhennersdorffrom 1947 to 1955, and in the sub sequent two years he apprenticed to a grocer (and really sold fish). From 1958 to 1962 he attended a school in Chemnitz, and from 1962 to 1967, in the heyday of Soviet mathematics, he was a student of mathematics at the Lomonosov University in Moscow. His lecturers included such eminent mathematicians as P.S. Alexan drov, A.G. Kurosh, and G.E. Shilov. His diploma paper was supervised by E.A. Gorin and A.Ya. Helemskii and was devoted to the structure of radicals in certain normed rings. Since 1966 he has been married to Ludmilla Pavlovna; their children Sergej and Katja were born in 1971 and 1974. In 1967, Silber mann moved back to Chemnitz and started working under the supervision of Siegfried Prossdorf. 1967-1969. First beat of the drum Following the advice of Prossdorf, he embarked on singular integral, Toeplitz and Wiener-Hopf operators whose symbols have zeros. From the work of Chebotarev, Cherskii, Dybin, Haikin, Karapetyants, and Prossdorf, to mention only a few prin cipal figures, it was known that if the symbol is in Coo and has only a finite number of zeros of integral orders, then the corresponding Toeplitz operator is not normally solvable on the usual Banach spaces, but it is Fredholm on certain Frechet spaces of test functions and distributions. The big question of those days was whether the converse is true. Silbermann tackled this question and showed by an ingenious proof that the answer is yes: if a Toeplitz operator with a Coo symbol is Fredholm on the spaces of test functions or distributions mentioned, then the symbol has at most a finite number of zeros of integral orders. This result was a beat of the drum. It advanced him immediately to the first row of researchers in the field and it is up to the present the brightest star in the vault of Toeplitz operators whose symbols have zeros. The result is proved in Silbermann's paper "On singular inte gral operators in spaces of infinitely differentiable and generalized functions" (in Russian), which appeared in the then famous journal "Matematicheskie Issledova nia" in 1971. This paper is Silbermann's actual opus 1 (another paper appeared earlier but was written later), and it has become one of his most frequently cited papers. 2 A. Bottcher 1970-1977. The years with Prossdorf Within a short time, Silbermann grew from a student of Prossdorf's to a co worker of equal rank. Together they made numerous significant contributions to the theory of singular integral operators that are not normally solvable, and to projection methods for such operators. The other co-workers of Silbermann during that period were Uwe Kohler, Christian Meyer, Johannes Steinmiiller, Karla Rost, and Johannes Elschner. In 1970, Silbermann defended his Dr. rer. nat. thesis, and only four years later, in 1974, he completed his habilitation thesis. He was then 33 years old. One cannot remember those years without mentioning Israel Gohberg. He visited Chemnitz in the late 60s and it was on his suggestion that Prossdorf and Silbermann started working on projection methods for singular integral operators whose symbols have zeros. Moreover, in 1974, Georg Heinig came to Chemnitz. He had then just accomplished his PhD under Gohberg's supervision and brought a good deal of Gohberg's spirit to Chemnitz. In 1975, Prossdorf left Chemnitz and went to Berlin. The large amount of mathematics developed by Prossdorf and Silbermann during those years resulted in their book "Projektionsverfahren und die naherungsweise Losung singularer Glei chungen", which appeared in 1977. In 1976, Silbermann was appointed professor (Dozent) in Chemnitz. He then had one book and more than 20 published papers. In those times, this was an outstanding balance. 1978-1979. I entered the scene Now it is time to introduce myself. I became a mathematics student in Chemnitz in 1975. I attended Silbermann's lecture course Analysis I-III and was fascinated by his charismatic teaching ability. In 1977, a couple of weeks before Easter, I turned to him with the request for a research problem. I remember perfectly telling him that I intended to bridge the time until Easter by doing some research. He gave me a problem and added on his turn that he would be impressed if I solved it by Christmas. The problem was as follows. Prossdorf had shown that if a function on the unit circle is Holder continuous with the exponent a, then the partial sums of the Fourier series converge to the function in the ,8th Holder norm provided ,8 < a. Silbermann asked me to check whether such a result is also true locally, that is, whether the partial sums of the Fourier series of a function that is Holder continuous with the exponent a on some arc I converge in the ,8th Holder norm (,8 < a) to the function on every arc J properly contained in I. I solved the problem (in the negative), but this was in 1978, many months after the Christmas of 1977. Some time in the second half of the 70s, Silbermann learned of the formula (Pap)-l P = Pa-1P _ Pa-1Q(Qa-1Q)-lQa-1P from Anatoli Kozak of Rostov-on-Don. He fell in ardent love with this formula and was soon able to do real wonders with it. One of those miracles was a new proof
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