Erik Koelink – författare

This volume, "Theory and Applications of Special Functions," is d- icated to Mizan Rahman in honoring him for the many important c- tributions to the theory of special functions that he has made over the years, and still continues to make. Some of the papers were presented at a special session of the American Mathematical Society Annual Meeting in Baltimore, Maryland, in January 2003 organized by Mourad Ismail. Mizan Rahman's contributions are not only contained in his own - pers, but also indirectly in other papers for which he supplied useful and often essential information. We refer to the paper on his mathematics in this volume for more information. This paper contains some personal recollections and tries to describe Mizan Rahman's literary writings in his mother tongue, Bengali. An even more personal paper on Mizan Rahman is the letter by his sons, whom we thank for allowing us to reproduce it in this book. The theory of special functions is very much an application driven field of mathematics. This is a very old field, dating back to the 18th century when physicists and mathematician were looking for solutions of the fundamental differential equations of mathematical physics. Since then the field has grown enormously, and this book reflects only part of the known applications.

This volume, "Theory and Applications of Special Functions," is d- icated to Mizan Rahman in honoring him for the many important c- tributions to the theory of special functions that he has made over the years, and still continues to make. Some of the papers were presented at a special session of the American Mathematical Society Annual Meeting in Baltimore, Maryland, in January 2003 organized by Mourad Ismail. Mizan Rahman's contributions are not only contained in his own - pers, but also indirectly in other papers for which he supplied useful and often essential information. We refer to the paper on his mathematics in this volume for more information. This paper contains some personal recollections and tries to describe Mizan Rahman's literary writings in his mother tongue, Bengali. An even more personal paper on Mizan Rahman is the letter by his sons, whom we thank for allowing us to reproduce it in this book. The theory of special functions is very much an application driven field of mathematics. This is a very old field, dating back to the 18th century when physicists and mathematician were looking for solutions of the fundamental differential equations of mathematical physics. Since then the field has grown enormously, and this book reflects only part of the known applications.

This volume contains the proceedings of the virtual conference on Hypergeometry, Integrability and Lie Theory, held from December 7-11, 2020, which was dedicated to the 50th birthday of Jasper Stokman. The papers represent recent developments in the areas of representation theory, quantum integrable systems and special functions of hypergeometric type.

OrthogonalPolynomialsandSpecialFunctions(OPSF)is a veryoldbranchof mathematics having a very rich history. Many famous mathematicians have contributed to the subject: Euler's work on the gamma function, Gauss's and Riemann's work onthe hypergeometricfunctions andthe hypergeometric di?erentialequation,Abel's andJacobi'sworkonelliptic functions,andsoon. Usuallythespecialfunctionshavebeenintroducedto solveaspeci?cproblem, and many of them occurred in solving the di?erential equations describing a physical problem, e.g., the astronomerBessel introduced the functions named afterhiminhisworkonKepler'sproblemofthreebodiesmovingundermutual gravitation. So the subject OPSF is very classical and there have been very interesting developments through the centuries, and there have been numerous appli- tions to various branches of mathematics, e.g. combinatorics, representation theory,numbertheory,andapplicationstophysicsandastronomy,suchasthe afore-mentioned classical physical problems, but also integrable systems, - tics,quantumchemistry,etcetera.SoOPSFiswell-established,andverymuch driven by applications. The advent of the computer, ?rst thought to be fatal to the subject, turned out to be a stimulus, ?rst of all because it allowedmore detailed computations requiring special numerical algorithms, but mainly - cause it led to automatic summation routines, notably the WZ-method (see Koepf's contribution). So OPSF is a very lively branch of mathematics. Since more advanced courses on OPSF seldom appear in the curriculum, we felt the need for such courses for young researchers (graduate students and post-docs). A series of European summer schools was started with one in Laredo, Spain (2000) and one in Inzell, Germany (2001). This book contains the notes for the lectures of the summer school in Belgium in 2002, which took place from August 12-16, 2002, at the Katholieke Universiteit Leuven, Belgium.In2003asummerschoolinOPSFwillbeheldinCoimbra,Portugal.