DOCSLIB.ORG

A Course in Complex Analysis and Riemann Surfaces

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Course in Complex Analysis and Riemann Surfaces A Course in Complex Analysis and Riemann Surfaces Wilhelm Schlag Graduate Studies in Mathematics Volume 154 American Mathematical Society https://doi.org/10.1090//gsm/154 A Course in Complex Analysis and Riemann Surfaces Wilhelm Schlag Graduate Studies in Mathematics Volume 154 American Mathematical Society Providence, Rhode Island EDITORIAL COMMITTEE Dan Abramovich Daniel S. Freed Rafe Mazzeo (Chair) Gigliola Staffilani 2010 Mathematics Subject Classification. Primary 30-01, 30F10, 30F15, 30F20, 30F30, 30F35. For additional information and updates on this book, visit www.ams.org/bookpages/gsm-154 Library of Congress Cataloging-in-Publication Data Schlag, Wilhelm, 1969– A course in complex analysis and Riemann surfaces / Wilhelm Schlag. pages cm. – (Graduate studies in mathematics ; volume 154) Includes bibliographical references and index. ISBN 978-0-8218-9847-5 (alk. paper) 1. Riemann surfaces–Textbooks. 2. Functions of complex variables–Textbooks. I. Title. QA333.S37 2014 515.93–dc23 2014009993 Copying and reprinting. Individual readers of this publication, and nonprofit libraries acting for them, are permitted to make fair use of the material, such as to copy a chapter for use in teaching or research. Permission is granted to quote brief passages from this publication in reviews, provided the customary acknowledgment of the source is given. Republication, systematic copying, or multiple reproduction of any material in this publication is permitted only under license from the American Mathematical Society. Requests for such permission should be addressed to the Acquisitions Department, American Mathematical Society, 201 Charles Street, Providence, Rhode Island 02904-2294 USA. Requests can also be made by e-mail to [email protected]. c 2014 by Wilhelm Schlag. All rights reserved. Printed in the United States of America. ∞ The paper used in this book is acid-free and falls within the guidelines established to ensure permanence and durability. Visit the AMS home page at http://www.ams.org/ 10987654321 191817161514 Contents Preface vii Acknowledgments xv Chapter 1. From i to z: the basics of complex analysis 1 §1.1. The field of complex numbers 1 §1.2. Holomorphic, analytic, and conformal 4 §1.3. The Riemann sphere 9 §1.4. M¨obius transformations 11 §1.5. The hyperbolic plane and the Poincar´edisk 15 §1.6. Complex integration, Cauchy theorems 18 §1.7. Applications of Cauchy’s theorems 23 §1.8. Harmonic functions 33 §1.9. Problems 36 Chapter 2. From z to the Riemann mapping theorem: some finer points of basic complex analysis 41 §2.1. The winding number 41 §2.2. The global form of Cauchy’s theorem 45 §2.3. Isolated singularities and residues 47 §2.4. Analytic continuation 56 §2.5. Convergence and normal families 60 §2.6. The Mittag-Leffler and Weierstrass theorems 63 §2.7. The Riemann mapping theorem 69 §2.8. Runge’s theorem and simple connectivity 74 iii iv Contents §2.9. Problems 79 Chapter 3. Harmonic functions 85 §3.1. The Poisson kernel 85 §3.2. The Poisson kernel from the probabilistic point of view 91 §3.3. Hardy classes of harmonic functions 95 §3.4. Almost everywhere convergence to the boundary data 100 §3.5. Hardy spaces of analytic functions 105 §3.6. Riesz theorems 109 §3.7. Entire functions of finite order 111 §3.8. A gallery of conformal plots 117 §3.9. Problems 122 Chapter 4. Riemann surfaces: definitions, examples, basic properties 129 §4.1. The basic definitions 129 §4.2. Examples and constructions of Riemann surfaces 131 §4.3. Functions on Riemann surfaces 143 §4.4. Degree and genus 146 §4.5. Riemann surfaces as quotients 148 §4.6. Elliptic functions 151 §4.7. Covering the plane with two or more points removed 160 §4.8. Groups of M¨obius transforms 164 §4.9. Problems 174 Chapter 5. Analytic continuation, covering surfaces, and algebraic functions 179 §5.1. Analytic continuation 179 §5.2. The unramified Riemann surface of an analytic germ 185 §5.3. The ramified Riemann surface of an analytic germ 189 §5.4. Algebraic germs and functions 192 §5.5. Algebraic equations generated by compact surfaces 199 §5.6. Some compact surfaces and their associated polynomials 206 §5.7. ODEs with meromorphic coefficients 211 §5.8. Problems 221 Chapter 6. Differential forms on Riemann surfaces 225 §6.1. Holomorphic and meromorphic differentials 225 §6.2. Integrating differentials and residues 227 Contents v §6.3. The Hodge-∗ operator and harmonic differentials 230 §6.4. Statement and examples of the Hodge decomposition 236 §6.5. Weyl’s lemma and the Hodge decomposition 244 §6.6. Existence of nonconstant meromorphic functions 250 §6.7. Examples of meromorphic functions and differentials 258 §6.8. Problems 266 Chapter 7. The Theorems of Riemann-Roch, Abel, and Jacobi 269 §7.1. Homology bases and holomorphic differentials 269 §7.2. Periods and bilinear relations 273 §7.3. Divisors 280 §7.4. The Riemann-Roch theorem 285 §7.5. Applications and general divisors 289 §7.6. Applications to algebraic curves 292 §7.7. The theorems of Abel and Jacobi 295 §7.8. Problems 303 Chapter 8. Uniformization 305 §8.1. Green functions and Riemann mapping 306 §8.2. Perron families 310 §8.3. Solution of Dirichlet’s problem 314 §8.4. Green’s functions on Riemann surfaces 317 §8.5. Uniformization for simply-connected surfaces 326 §8.6. Uniformization of non-simply-connected surfaces 335 §8.7. Fuchsian groups 338 §8.8. Problems 349 Appendix A. Review of some basic background material 353 §A.1. Geometry and topology 353 §A.2. Algebra 363 §A.3. Analysis 365 Bibliography 371 Index 377 Preface During their first year at the University of Chicago, graduate students in mathematics take classes in algebra, analysis, and geometry, one of each every quarter. The analysis courses typically cover real analysis and measure theory, functional analysis and applications, and complex analysis. This book grew out of the author’s notes for the complex analysis classes which he taught during the Spring quarters of 2007 and 2008. These courses covered elementary aspects of complex analysis such as the Cauchy integral theorem, the residue theorem, Laurent series, and the Riemann mapping theorem, but also more advanced material selected from Riemann surface theory. Needless to say, all of these topics have been covered in excellent text- books as well as classic treatises. This book does not try to compete with the works of the old masters such as Ahlfors [1, 2], Hurwitz–Courant [44], Titchmarsh [80], Ahlfors–Sario [3], Nevanlinna [67], and Weyl [88]. Rather, it is intended as a fairly detailed, yet fast-paced introduction to those parts of the theory of one complex variable that seem most useful in other ar- eas of mathematics (geometric group theory, dynamics, algebraic geometry, number theory, functional analysis). There is no question that complex analysis is a cornerstone of a math- ematics specialization at every university and each area of mathematics re- quires at least some knowledge of it. However, many mathematicians never take more than an introductory class in complex variables which ends up being awkward and slightly outmoded. Often this is due to the omission of Riemann surfaces and the assumption of a computational, rather than a geometric point of view. The author has therefore tried to emphasize the intuitive geometric un- derpinnings of elementary complex analysis that naturally lead to Riemann vii viii Preface surface theory. Today this is either not taught at all, given an algebraic slant, or is presented from a sophisticated analytical perspective, leaving the students without any foundation, intuition, historical understanding, let alone a working knowledge of the subject. This book intends to develop the subject of Riemann surfaces as a nat- ural continuation of the elementary theory without which basic complex analysis would indeed seem artificial and antiquated. At the same time, we do not overly emphasize the algebraic aspects such as applications to elliptic curves. The author feels that those students who wish to pursue this direction will be able to do so quite easily after mastering the material in this book. Because of this, as well as numerous other omissions (e.g., zeta, theta, and automorphic functions, Serre duality, Dolbeault cohomol- ogy) and the reasonably short length of the book, it is to be considered as an “intermediate introduction”. Partly due to the fact that the Chicago first year curriculum covers a fair amount of topology and geometry before complex analysis, this book assumes knowledge of basic notions such as homotopy, the fundamental group, differential forms, cohomology and homology, and from algebra we require knowledge of the notions of groups and fields, and some familiarity with the resultant of two polynomials (but the latter is needed only for the definition of the Riemann surfaces of an algebraic germ). However, for the most part merely the most elementary familiarity of these concepts is assumed and we collect the few facts that we do need in Appendix A. As far as analytical prerequisites are concerned, they are fairly low, not extending far beyond multi-variable calculus and basic Hilbert space theory (in Chapter 6 we use orthogonal projections). One exception to this occurs in Sections 3.3, 3.4, and 3.5, which use the weak and weak-∗ topologies in Lp and the space of measures (Riesz representation theorem). Again, what we need is recalled in the appendix. Let us now describe the contents of the individual chapters in more detail. Chapter 1 introduces the concept of differentiability over C,the calculus of ∂z,∂z¯, the Cauchy-Riemann equations, power series, the M¨obius (or fractional linear) transformations and the Riemann sphere. Applications of these transformations to hyperbolic geometry (the Poincar´e disk and the upper half-plane models) are also discussed.
Load more

Recommended publications
  • The Integral Geometry of Line Complexes and a Theorem of Gelfand-Graev Astérisque, Tome S131 (1985), P
    Astérisque VICTOR GUILLEMIN The integral geometry of line complexes and a theorem of Gelfand-Graev Astérisque, tome S131 (1985), p. 135-149 <http://www.numdam.org/item?id=AST_1985__S131__135_0> © Société mathématique de France, 1985, tous droits réservés. L’accès aux archives de la collection « Astérisque » (http://smf4.emath.fr/ Publications/Asterisque/) implique l’accord avec les conditions générales d’uti- lisation (http://www.numdam.org/conditions). Toute utilisation commerciale ou impression systématique est constitutive d’une infraction pénale. Toute copie ou impression de ce fichier doit contenir la présente mention de copyright. Article numérisé dans le cadre du programme Numérisation de documents anciens mathématiques http://www.numdam.org/ Société Mathématique de France Astérisque, hors série, 1985, p. 135-149 THE INTEGRAL GEOMETRY OF LINE COMPLEXES AND A THEOREM OF GELFAND-GRAEV BY Victor GUILLEMIN 1. Introduction Let P = CP3 be the complex three-dimensional projective space and let G = CG(2,4) be the Grassmannian of complex two-dimensional subspaces of C4. To each point p E G corresponds a complex line lp in P. Given a smooth function, /, on P we will show in § 2 how to define properly the line integral, (1.1) f(\)d\ d\. = f(p). d A complex hypersurface, 5, in G is called admissible if there exists no smooth function, /, which is not identically zero but for which the line integrals, (1,1) are zero for all p G 5. In other words if S is admissible, then, in principle, / can be determined by its integrals over the lines, Zp, p G 5. In the 60's GELFAND and GRAEV settled the problem of characterizing which subvarieties, 5, of G have this property.
    [Show full text]
  • Riemann Surfaces
    RIEMANN SURFACES AARON LANDESMAN CONTENTS 1. Introduction 2 2. Maps of Riemann Surfaces 4 2.1. Defining the maps 4 2.2. The multiplicity of a map 4 2.3. Ramification Loci of maps 6 2.4. Applications 6 3. Properness 9 3.1. Definition of properness 9 3.2. Basic properties of proper morphisms 9 3.3. Constancy of degree of a map 10 4. Examples of Proper Maps of Riemann Surfaces 13 5. Riemann-Hurwitz 15 5.1. Statement of Riemann-Hurwitz 15 5.2. Applications 15 6. Automorphisms of Riemann Surfaces of genus ≥ 2 18 6.1. Statement of the bound 18 6.2. Proving the bound 18 6.3. We rule out g(Y) > 1 20 6.4. We rule out g(Y) = 1 20 6.5. We rule out g(Y) = 0, n ≥ 5 20 6.6. We rule out g(Y) = 0, n = 4 20 6.7. We rule out g(C0) = 0, n = 3 20 6.8. 21 7. Automorphisms in low genus 0 and 1 22 7.1. Genus 0 22 7.2. Genus 1 22 7.3. Example in Genus 3 23 Appendix A. Proof of Riemann Hurwitz 25 Appendix B. Quotients of Riemann surfaces by automorphisms 29 References 31 1 2 AARON LANDESMAN 1. INTRODUCTION In this course, we’ll discuss the theory of Riemann surfaces. Rie- mann surfaces are a beautiful breeding ground for ideas from many areas of math. In this way they connect seemingly disjoint fields, and also allow one to use tools from different areas of math to study them.
    [Show full text]
  • All That Math Portraits of Mathematicians As Young Researchers
    Downloaded from orbit.dtu.dk on: Oct 06, 2021 All that Math Portraits of mathematicians as young researchers Hansen, Vagn Lundsgaard Published in: EMS Newsletter Publication date: 2012 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Hansen, V. L. (2012). All that Math: Portraits of mathematicians as young researchers. EMS Newsletter, (85), 61-62. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. NEWSLETTER OF THE EUROPEAN MATHEMATICAL SOCIETY Editorial Obituary Feature Interview 6ecm Marco Brunella Alan Turing’s Centenary Endre Szemerédi p. 4 p. 29 p. 32 p. 39 September 2012 Issue 85 ISSN 1027-488X S E European M M Mathematical E S Society Applied Mathematics Journals from Cambridge journals.cambridge.org/pem journals.cambridge.org/ejm journals.cambridge.org/psp journals.cambridge.org/flm journals.cambridge.org/anz journals.cambridge.org/pes journals.cambridge.org/prm journals.cambridge.org/anu journals.cambridge.org/mtk Receive a free trial to the latest issue of each of our mathematics journals at journals.cambridge.org/maths Cambridge Press Applied Maths Advert_AW.indd 1 30/07/2012 12:11 Contents Editorial Team Editors-in-Chief Jorge Buescu (2009–2012) European (Book Reviews) Vicente Muñoz (2005–2012) Dep.
    [Show full text]
  • Riemannian Geometry Andreas Kriegl Email:[email protected]
    Riemannian Geometry Andreas Kriegl email:[email protected] 250067, WS 2018, Mo. 945-1030 and Th. 900-945 at SR9 z y x This is preliminary english version of the script for my homonymous lecture course in the Winter Semester 2018. It was translated from the german original using a pre and post processor (written by myself) for google translate. Due to the limitations of google translate { see the following article by Douglas Hofstadter www.theatlantic.com/. /551570 { heavy corrections by hand had to be done af- terwards. However, it is still a rather rough translation which I will try to improve during the semester. It consists of selected parts of the much more comprehensive differential geometry script (in german), which is also available as a PDF file under http://www.mat.univie.ac.at/∼kriegl/Skripten/diffgeom.pdf. In choosing the content, I followed the curricula, so the following topics should be considered: • Levi-Civita connection • Geodesics • Completeness • Hopf-Rhinov theoroem • Selected further topics from Riemannian geometry. Prerequisite is the lecture course 'Analysis on Manifolds'. The structure of the script is thus the following: Chapter I deals with isometries and conformal mappings as well as Riemann sur- faces - i.e. 2-dimensional Riemannian manifolds - and their relation to complex analysis. In Chapter II we look again at differential forms in the context of Riemannian manifolds, in particular the gradient, divergence, the Hodge star operator, and most importantly, the Laplace Beltrami operator. As a possible first application, a section on classical mechanics is included. In Chapter III we first develop the concept of curvature for plane curves and space curves, then for hypersurfaces, and finally for Riemannian manifolds.
    [Show full text]
  • CR Singular Immersions of Complex Projective Spaces
    Beitr¨agezur Algebra und Geometrie Contributions to Algebra and Geometry Volume 43 (2002), No. 2, 451-477. CR Singular Immersions of Complex Projective Spaces Adam Coffman∗ Department of Mathematical Sciences Indiana University Purdue University Fort Wayne Fort Wayne, IN 46805-1499 e-mail: Coff[email protected] Abstract. Quadratically parametrized smooth maps from one complex projective space to another are constructed as projections of the Segre map of the complexifi- cation. A classification theorem relates equivalence classes of projections to congru- ence classes of matrix pencils. Maps from the 2-sphere to the complex projective plane, which generalize stereographic projection, and immersions of the complex projective plane in four and five complex dimensions, are considered in detail. Of particular interest are the CR singular points in the image. MSC 2000: 14E05, 14P05, 15A22, 32S20, 32V40 1. Introduction It was shown by [23] that the complex projective plane CP 2 can be embedded in R7. An example of such an embedding, where R7 is considered as a subspace of C4, and CP 2 has complex homogeneous coordinates [z1 : z2 : z3], was given by the following parametric map: 1 2 2 [z1 : z2 : z3] 7→ 2 2 2 (z2z¯3, z3z¯1, z1z¯2, |z1| − |z2| ). |z1| + |z2| + |z3| Another parametric map of a similar form embeds the complex projective line CP 1 in R3 ⊆ C2: 1 2 2 [z0 : z1] 7→ 2 2 (2¯z0z1, |z1| − |z0| ). |z0| + |z1| ∗The author’s research was supported in part by a 1999 IPFW Summer Faculty Research Grant. 0138-4821/93 $ 2.50 c 2002 Heldermann Verlag 452 Adam Coffman: CR Singular Immersions of Complex Projective Spaces This may look more familiar when restricted to an affine neighborhood, [z0 : z1] = (1, z) = (1, x + iy), so the set of complex numbers is mapped to the unit sphere: 2x 2y |z|2 − 1 z 7→ ( , , ), 1 + |z|2 1 + |z|2 1 + |z|2 and the “point at infinity”, [0 : 1], is mapped to the point (0, 0, 1) ∈ R3.
    [Show full text]
  • KLEIN's EVANSTON LECTURES. the Evanston Colloquium : Lectures on Mathematics, Deliv­ Ered from Aug
    1894] KLEIN'S EVANSTON LECTURES, 119 KLEIN'S EVANSTON LECTURES. The Evanston Colloquium : Lectures on mathematics, deliv­ ered from Aug. 28 to Sept. 9,1893, before members of the Congress of Mai hematics held in connection with the World's Fair in Chicago, at Northwestern University, Evanston, 111., by FELIX KLEIN. Reported by Alexander Ziwet. New York, Macniillan, 1894. 8vo. x and 109 pp. THIS little volume occupies a somewhat unicrue position in mathematical literature. Even the Commission permanente would find it difficult to classify it and would have to attach a bewildering series of symbols to characterize its contents. It is stated as the object of these lectures " to pass in review some of the principal phases of the most recent development of mathematical thought in Germany" ; and surely, no one could be more competent to do this than Professor Felix Klein. His intimate personal connection with this develop­ ment is evidenced alike by the long array of his own works and papers, and by those of the numerous pupils and followers he has inspired. Eut perhaps even more than on this account is he fitted for this task by the well-known comprehensiveness of his knowledge and the breadth of view so -characteristic of all his work. In these lectures there is little strictly mathematical reason­ ing, but a great deal of information and expert comment on the most advanced work done in pure mathematics during the last twenty-five years. Happily this is given with such freshness and vigor of style as makes the reading a recreation.
    [Show full text]
  • VECTOR BUNDLES OVER a REAL ELLIPTIC CURVE 3 Admit a Canonical Real Structure If K Is Even and a Canonical Quaternionic Structure If K Is Odd
    VECTOR BUNDLES OVER A REAL ELLIPTIC CURVE INDRANIL BISWAS AND FLORENT SCHAFFHAUSER Abstract. Given a geometrically irreducible smooth projective curve of genus 1 defined over the field of real numbers, and a pair of integers r and d, we deter- mine the isomorphism class of the moduli space of semi-stable vector bundles of rank r and degree d on the curve. When r and d are coprime, we describe the topology of the real locus and give a modular interpretation of its points. We also study, for arbitrary rank and degree, the moduli space of indecom- posable vector bundles of rank r and degree d, and determine its isomorphism class as a real algebraic variety. Contents 1. Introduction 1 1.1. Notation 1 1.2. The case of genus zero 2 1.3. Description of the results 3 2. Moduli spaces of semi-stable vector bundles over an elliptic curve 5 2.1. Real elliptic curves and their Picard varieties 5 2.2. Semi-stable vector bundles 6 2.3. The real structure of the moduli space 8 2.4. Topologyofthesetofrealpointsinthecoprimecase 10 2.5. Real vector bundles of fixed determinant 12 3. Indecomposable vector bundles 13 3.1. Indecomposable vector bundles over a complex elliptic curve 13 3.2. Relation to semi-stable and stable bundles 14 3.3. Indecomposable vector bundles over a real elliptic curve 15 References 17 arXiv:1410.6845v2 [math.AG] 8 Jan 2016 1. Introduction 1.1. Notation. In this paper, a real elliptic curve will be a triple (X, x0, σ) where (X, x0) is a complex elliptic curve (i.e., a compact connected Riemann surface of genus 1 with a marked point x0) and σ : X −→ X is an anti-holomorphic involution (also called a real structure).
    [Show full text]
  • Lectures on the Combinatorial Structure of the Moduli Spaces of Riemann Surfaces
    LECTURES ON THE COMBINATORIAL STRUCTURE OF THE MODULI SPACES OF RIEMANN SURFACES MOTOHICO MULASE Contents 1. Riemann Surfaces and Elliptic Functions 1 1.1. Basic Definitions 1 1.2. Elementary Examples 3 1.3. Weierstrass Elliptic Functions 10 1.4. Elliptic Functions and Elliptic Curves 13 1.5. Degeneration of the Weierstrass Elliptic Function 16 1.6. The Elliptic Modular Function 19 1.7. Compactification of the Moduli of Elliptic Curves 26 References 31 1. Riemann Surfaces and Elliptic Functions 1.1. Basic Definitions. Let us begin with defining Riemann surfaces and their moduli spaces. Definition 1.1 (Riemann surfaces). A Riemann surface is a paracompact Haus- S dorff topological space C with an open covering C = λ Uλ such that for each open set Uλ there is an open domain Vλ of the complex plane C and a homeomorphism (1.1) φλ : Vλ −→ Uλ −1 that satisfies that if Uλ ∩ Uµ 6= ∅, then the gluing map φµ ◦ φλ φ−1 (1.2) −1 φλ µ −1 Vλ ⊃ φλ (Uλ ∩ Uµ) −−−−→ Uλ ∩ Uµ −−−−→ φµ (Uλ ∩ Uµ) ⊂ Vµ is a biholomorphic function. Remark. (1) A topological space X is paracompact if for every open covering S S X = λ Uλ, there is a locally finite open cover X = i Vi such that Vi ⊂ Uλ for some λ. Locally finite means that for every x ∈ X, there are only finitely many Vi’s that contain x. X is said to be Hausdorff if for every pair of distinct points x, y of X, there are open neighborhoods Wx 3 x and Wy 3 y such that Wx ∩ Wy = ∅.
    [Show full text]
  • The Riemann-Roch Theorem Is a Special Case of the Atiyah-Singer Index Formula
    S.C. Raynor The Riemann-Roch theorem is a special case of the Atiyah-Singer index formula Master thesis defended on 5 March, 2010 Thesis supervisor: dr. M. L¨ubke Mathematisch Instituut, Universiteit Leiden Contents Introduction 5 Chapter 1. Review of Basic Material 9 1. Vector bundles 9 2. Sheaves 18 Chapter 2. The Analytic Index of an Elliptic Complex 27 1. Elliptic differential operators 27 2. Elliptic complexes 30 Chapter 3. The Riemann-Roch Theorem 35 1. Divisors 35 2. The Riemann-Roch Theorem and the analytic index of a divisor 40 3. The Euler characteristic and Hirzebruch-Riemann-Roch 42 Chapter 4. The Topological Index of a Divisor 45 1. De Rham Cohomology 45 2. The genus of a Riemann surface 46 3. The degree of a divisor 48 Chapter 5. Some aspects of algebraic topology and the T-characteristic 57 1. Chern classes 57 2. Multiplicative sequences and the Todd polynomials 62 3. The Todd class and the Chern Character 63 4. The T-characteristic 65 Chapter 6. The Topological Index of the Dolbeault operator 67 1. Elements of topological K-theory 67 2. The difference bundle associated to an elliptic operator 68 3. The Thom Isomorphism 71 4. The Todd genus is a special case of the topological index 76 Appendix: Elliptic complexes and the topological index 81 Bibliography 85 3 Introduction The Atiyah-Singer index formula equates a purely analytical property of an elliptic differential operator P (resp. elliptic complex E) on a compact manifold called the analytic index inda(P ) (resp. inda(E)) with a purely topological prop- erty, the topological index indt(P )(resp.
    [Show full text]
  • EMS Newsletter September 2012 1 EMS Agenda EMS Executive Committee EMS Agenda
    NEWSLETTER OF THE EUROPEAN MATHEMATICAL SOCIETY Editorial Obituary Feature Interview 6ecm Marco Brunella Alan Turing’s Centenary Endre Szemerédi p. 4 p. 29 p. 32 p. 39 September 2012 Issue 85 ISSN 1027-488X S E European M M Mathematical E S Society Applied Mathematics Journals from Cambridge journals.cambridge.org/pem journals.cambridge.org/ejm journals.cambridge.org/psp journals.cambridge.org/flm journals.cambridge.org/anz journals.cambridge.org/pes journals.cambridge.org/prm journals.cambridge.org/anu journals.cambridge.org/mtk Receive a free trial to the latest issue of each of our mathematics journals at journals.cambridge.org/maths Cambridge Press Applied Maths Advert_AW.indd 1 30/07/2012 12:11 Contents Editorial Team Editors-in-Chief Jorge Buescu (2009–2012) European (Book Reviews) Vicente Muñoz (2005–2012) Dep. Matemática, Faculdade Facultad de Matematicas de Ciências, Edifício C6, Universidad Complutense Piso 2 Campo Grande Mathematical de Madrid 1749-006 Lisboa, Portugal e-mail: [email protected] Plaza de Ciencias 3, 28040 Madrid, Spain Eva-Maria Feichtner e-mail: [email protected] (2012–2015) Society Department of Mathematics Lucia Di Vizio (2012–2016) Université de Versailles- University of Bremen St Quentin 28359 Bremen, Germany e-mail: [email protected] Laboratoire de Mathématiques Newsletter No. 85, September 2012 45 avenue des États-Unis Eva Miranda (2010–2013) 78035 Versailles cedex, France Departament de Matemàtica e-mail: [email protected] Aplicada I EMS Agenda .......................................................................................................................................................... 2 EPSEB, Edifici P Editorial – S. Jackowski ........................................................................................................................... 3 Associate Editors Universitat Politècnica de Catalunya Opening Ceremony of the 6ECM – M.
    [Show full text]
  • An Introduction to Complex Analysis and Geometry John P. D'angelo
    An Introduction to Complex Analysis and Geometry John P. D'Angelo Dept. of Mathematics, Univ. of Illinois, 1409 W. Green St., Urbana IL 61801 [email protected] 1 2 c 2009 by John P. D'Angelo Contents Chapter 1. From the real numbers to the complex numbers 11 1. Introduction 11 2. Number systems 11 3. Inequalities and ordered fields 16 4. The complex numbers 24 5. Alternative definitions of C 26 6. A glimpse at metric spaces 30 Chapter 2. Complex numbers 35 1. Complex conjugation 35 2. Existence of square roots 37 3. Limits 39 4. Convergent infinite series 41 5. Uniform convergence and consequences 44 6. The unit circle and trigonometry 50 7. The geometry of addition and multiplication 53 8. Logarithms 54 Chapter 3. Complex numbers and geometry 59 1. Lines, circles, and balls 59 2. Analytic geometry 62 3. Quadratic polynomials 63 4. Linear fractional transformations 69 5. The Riemann sphere 73 Chapter 4. Power series expansions 75 1. Geometric series 75 2. The radius of convergence 78 3. Generating functions 80 4. Fibonacci numbers 82 5. An application of power series 85 6. Rationality 87 Chapter 5. Complex differentiation 91 1. Definitions of complex analytic function 91 2. Complex differentiation 92 3. The Cauchy-Riemann equations 94 4. Orthogonal trajectories and harmonic functions 97 5. A glimpse at harmonic functions 98 6. What is a differential form? 103 3 4 CONTENTS Chapter 6. Complex integration 107 1. Complex-valued functions 107 2. Line integrals 109 3. Goursat's proof 116 4. The Cauchy integral formula 119 5.
    [Show full text]
  • Complex Algebraic Geometry
    Complex Algebraic Geometry Jean Gallier∗ and Stephen S. Shatz∗∗ ∗Department of Computer and Information Science University of Pennsylvania Philadelphia, PA 19104, USA e-mail: [email protected] ∗∗Department of Mathematics University of Pennsylvania Philadelphia, PA 19104, USA e-mail: [email protected] February 25, 2011 2 Contents 1 Complex Algebraic Varieties; Elementary Theory 7 1.1 What is Geometry & What is Complex Algebraic Geometry? . .......... 7 1.2 LocalStructureofComplexVarieties. ............ 14 1.3 LocalStructureofComplexVarieties,II . ............. 28 1.4 Elementary Global Theory of Varieties . ........... 42 2 Cohomologyof(Mostly)ConstantSheavesandHodgeTheory 73 2.1 RealandComplex .................................... ...... 73 2.2 Cohomology,deRham,Dolbeault. ......... 78 2.3 Hodge I, Analytic Preliminaries . ........ 89 2.4 Hodge II, Globalization & Proof of Hodge’s Theorem . ............ 107 2.5 HodgeIII,TheK¨ahlerCase . .......... 131 2.6 Hodge IV: Lefschetz Decomposition & the Hard Lefschetz Theorem............... 147 2.7 ExtensionsofResultstoVectorBundles . ............ 162 3 The Hirzebruch-Riemann-Roch Theorem 165 3.1 Line Bundles, Vector Bundles, Divisors . ........... 165 3.2 ChernClassesandSegreClasses . .......... 179 3.3 The L-GenusandtheToddGenus .............................. 215 3.4 CobordismandtheSignatureTheorem. ........... 227 3.5 The Hirzebruch–Riemann–Roch Theorem (HRR) . ............ 232 3 4 CONTENTS Preface This manuscript is based on lectures given by Steve Shatz for the course Math 622/623–Complex Algebraic Geometry, during Fall 2003 and Spring 2004. The process for producing this manuscript was the following: I (Jean Gallier) took notes and transcribed them in LATEX at the end of every week. A week later or so, Steve reviewed these notes and made changes and corrections. After the course was over, Steve wrote up additional material that I transcribed into LATEX. The following manuscript is thus unfinished and should be considered as work in progress.
    [Show full text]