Handbook of Complex Analysis Handbook of Complex Analysis Edited by Steven G. Krantz First edition published 2022 by CRC Press 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742 and by CRC Press 4 Park Square, Milton Park, Abingdon, Oxon, OX14 4RN © 2022 Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, LLC Reasonable efforts have been made to publish reliable data and information, but the author and pub- lisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged, please write and let us know so we may rectify it in any future reprint. 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Contents Preface vii Editor ix List of Contributors xi 1 Something about Poisson and Dirichlet 1 Steven R. Bell and Luis Reyna de la Torre 2 The Cauchy-Leray Operator for Convex Domains 19 David Barrett and Michael Bolt 3 Fractional Linear Maps and Some Applications. An “Augenblick”. 41 Joseph A. Cima 4 Biholomorphic Transformations 61 Buma Fridman and Daowei Ma 5 Positivity in the ∂¯-Neumann Problem 89 Siqi Fu 6 Symmetry and Art 133 Emily Gullerud and James S. Walker 7 A Glimpse into Invariant Distances in Complex Analysis 171 Marek Jarnicki and Peter Pflug 8 Variations on the (Eternal) Theme of Analytic Continuation 229 Dmitry Khavinson 9 Complex Convexity 245 Christer Oscar Kiselman 10 Reproducing Kernels in Complex Analysis 379 Steven G. Krantz v vi Contents 11 The Green’s Function Method for the Riemann Mapping Theorem 427 Bingyuan Liu 12 PolynomialTraceIdentitiesinSL(2,C),QuaternionAlgebras, and Two-Generator Kleinian Groups 433 T. H. Marshall and Gaven Martin 13 Boundary Value Problems on Klein Surfaces 487 Vicentiu Radulescu and Monica Rosiu Index 521 Preface Despite being nearly 500 years old, with work dating back to Cardano, Euler, Gauss, Cauchy, Riemann, and many others, the subject of complex analysis is still today a vital and active part of the mathematical sciences. In addition to all the exciting theoretical work being done today, there are important ap- plicationstophysics,engineering,cosmology,andotheraspectsoftechnology. Many of the world’s most distinguished and accomplished mathematicians conduct research in complex analysis. Several recent Fields Medalists study complex analysis. Although a venerable subject, complex analysis continues to grow and prosper. New directions of development in the subject include dynamical sys- tems, quasiconformal mappings, harmonic measure, automorphism groups, and the list can go on at some length. One of the sources of strength for the subject is its interaction with diverse parts of mathematics, including dif- ferential geometry, partial differential equations, functional analysis, algebra, combinatorics, and many other aspects of the subject. This Handbook of Complex Analysis presents contributed chapters by several distinguished mathematicians, including a new generation of re- searchers. More than a compilation of recent results, this book offers a step- ping stone for students to gain entry into the professional life of complex analysis.Theessayspresentedhereareallaccessibletograduatestudentsbut will also be of considerable interest to the seasoned mathematician. Classes and seminars, of course, play a role in the maturation process that we are describing. But more is needed for the unilateral study. This handbook will play such a role. Asnoted,thisbookwillserveasareferenceandasourceofinspirationfor maturemathematicians—bothspecialistsincomplexanalysisandotherswho want to become acquainted with current modes of thought and investigation. And it will help the neophyte to become inured in the subject matter. Thechaptersinthisvolumeareauthoredbyleadingexpertsinthesubject area,alsogiftedexpositors.Theyarecarefullycraftedpresentationsofdiverse aspects of the field, formulated for a broad and diverse audience. The editor intends this volume to be a touchstone for current ideas in the broadly con- strued subject area of complex analysis. It should enrich the literature and point to some new directions. The point here is not to present an epitaph for complex analysis but rather to provide an entree to a whole new life. We anticipate that the reader of this volume will be eager to explore other parts of complex analysis literature and to begin to play an active role in complex analysis research life. vii Editor Steven G. Krantz is a professor of mathematics at Washington Univer- sity in St. Louis. He has previously taught at UCLA, Princeton University, and Pennsylvania State University. He has written more than 130 books and more than 250 scholarly papers and is the founding editor of the Journal of Geometric Analysis. An AMS Fellow, Dr. Krantz has been a recipient of the Chauvenet Prize, Beckenbach Book Award, and Kemper Prize. He received a PhD from Princeton University. ix