Introduction to Algebraic Geometry
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Fundamental Algebraic Geometry
http://dx.doi.org/10.1090/surv/123 hematical Surveys and onographs olume 123 Fundamental Algebraic Geometry Grothendieck's FGA Explained Barbara Fantechi Lothar Gottsche Luc lllusie Steven L. Kleiman Nitin Nitsure AngeloVistoli American Mathematical Society U^VDED^ EDITORIAL COMMITTEE Jerry L. Bona Peter S. Landweber Michael G. Eastwood Michael P. Loss J. T. Stafford, Chair 2000 Mathematics Subject Classification. Primary 14-01, 14C20, 13D10, 14D15, 14K30, 18F10, 18D30. For additional information and updates on this book, visit www.ams.org/bookpages/surv-123 Library of Congress Cataloging-in-Publication Data Fundamental algebraic geometry : Grothendieck's FGA explained / Barbara Fantechi p. cm. — (Mathematical surveys and monographs, ISSN 0076-5376 ; v. 123) Includes bibliographical references and index. ISBN 0-8218-3541-6 (pbk. : acid-free paper) ISBN 0-8218-4245-5 (soft cover : acid-free paper) 1. Geometry, Algebraic. 2. Grothendieck groups. 3. Grothendieck categories. I Barbara, 1966- II. Mathematical surveys and monographs ; no. 123. QA564.F86 2005 516.3'5—dc22 2005053614 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. -
Algebraic Curves and Surfaces
Notes for Curves and Surfaces Instructor: Robert Freidman Henry Liu April 25, 2017 Abstract These are my live-texed notes for the Spring 2017 offering of MATH GR8293 Algebraic Curves & Surfaces . Let me know when you find errors or typos. I'm sure there are plenty. 1 Curves on a surface 1 1.1 Topological invariants . 1 1.2 Holomorphic invariants . 2 1.3 Divisors . 3 1.4 Algebraic intersection theory . 4 1.5 Arithmetic genus . 6 1.6 Riemann{Roch formula . 7 1.7 Hodge index theorem . 7 1.8 Ample and nef divisors . 8 1.9 Ample cone and its closure . 11 1.10 Closure of the ample cone . 13 1.11 Div and Num as functors . 15 2 Birational geometry 17 2.1 Blowing up and down . 17 2.2 Numerical invariants of X~ ...................................... 18 2.3 Embedded resolutions for curves on a surface . 19 2.4 Minimal models of surfaces . 23 2.5 More general contractions . 24 2.6 Rational singularities . 26 2.7 Fundamental cycles . 28 2.8 Surface singularities . 31 2.9 Gorenstein condition for normal surface singularities . 33 3 Examples of surfaces 36 3.1 Rational ruled surfaces . 36 3.2 More general ruled surfaces . 39 3.3 Numerical invariants . 41 3.4 The invariant e(V ).......................................... 42 3.5 Ample and nef cones . 44 3.6 del Pezzo surfaces . 44 3.7 Lines on a cubic and del Pezzos . 47 3.8 Characterization of del Pezzo surfaces . 50 3.9 K3 surfaces . 51 3.10 Period map . 54 a 3.11 Elliptic surfaces . -
Torification and Factorization of Birational Maps 3
TORIFICATION AND FACTORIZATION OF BIRATIONAL MAPS DAN ABRAMOVICH, KALLE KARU, KENJI MATSUKI, AND JAROSLAW WLODARCZYK Abstract. Building on work of the fourth author in [69], we prove the weak factorization conjecture for birational maps in characteristic zero: a birational map between complete nonsingular varieties over an algebraically closed field K of characteristic zero is a composite of blowings up and blowings down with smooth centers. Contents 0. Introduction 1 1. Preliminaries 5 2. Birational Cobordisms 10 3. Torification 16 4. A proof of the weak factorization theorem 22 5. Generalizations 24 6. Problems related to weak factorization 27 References 28 0. Introduction We work over an algebraically closed field K of characteristic 0. We denote the multiplicative group of K by K∗. 0.1. Statement of the main result. The purpose of this paper is to give a proof for the following weak factorization conjecture of birational maps. We note that another proof of this theorem was given by the fourth author in [70]. See section 0.12 for a brief comparison of the two approaches. Theorem 0.1.1 (Weak Factorization). Let φ : X1 99K X2 be a birational map between complete nonsingular algebraic varieties X1 and X2 over an algebraically closed field K of characteristic zero, and let U ⊂ X1 be an open set where φ is an isomorphism. Then φ can be factored into a sequence of blowings up and blowings arXiv:math/9904135v4 [math.AG] 31 May 2000 down with smooth irreducible centers disjoint from U, namely, there exists a sequence of birational maps between complete nonsingular algebraic varieties ϕ1 ϕ2 ϕi ϕi+1 ϕi+2 ϕl−1 ϕl X1 = V0 99K V1 99K · · · 99K Vi 99K Vi+1 99K · · · 99K Vl−1 99K Vl = X2 where 1. -
New York Journal of Mathematics Lang's Conjectures, Fibered
New York Journal of Mathematics New York J. Math. 2 (1996) 20–34. Lang’s Conjectures, Fibered Powers, and Uniformity Dan Abramovich and Jos´e Felipe Voloch Abstract. We prove that the fibered power conjecture of Caporaso et al. (Con- jecture H, [CHM], §6) together with Lang’s conjecture implies the uniformity of rational points on varieties of general type, as predicted in [CHM]; a few applications on the arithmetic and geometry of curves are stated. In an opposite direction, we give counterexamples to some analogous results in positive characteristic. We show that curves that change genus can have arbitrarily many rational points; and that curves over Fp(t) can have arbitrarily many Frobenius orbits of non-constant points. Contents 1. Introduction 21 1.1. A Few Conjectures of Lang 21 1.2. The Fibered Power Conjecture 22 1.3. Summary of Results on the Implication Side 22 1.4. Summary of Results: Examples in Positive Characteristic 24 1.5. Acknowledgments 25 2. Proof of Theorem 1.5 25 2.1. Preliminaries 25 2.2. Prolongable Points 25 2.3. Proof of Theorem 1.5 26 3. A Few Refinements and Applications in Arithmetic and Geometry 26 3.1. Proof of Theorem 1.6 26 3.2. Uniformity in Terms of the Degree of an Extension 27 3.3. The Geometric Case 28 4. Examples in Positive Characteristic 30 4.1. Curves that Change Genus 30 Received December 20, 1995. Mathematics Subject Classification. 14G; 11G. Key words and phrases. arithmetic geometry, Lang’s conjecture, rational points. Abramovich partially supported by NSF grant DMS-9503276. -
Moduli of K3 Surfaces and Irreducible Symplectic Manifolds
Moduli of K3 Surfaces and Irreducible Symplectic Manifolds V. Gritsenko, K. Hulek and G.K. Sankaran Abstract The name “K3 surfaces” was coined by A. Weil in 1957 when he formu- lated a research programme for these surfaces and their moduli. Since then, irreducible holomorphic symplectic manifolds have been intro- duced as a higher dimensional analogue of K3 surfaces. In this paper we present a review of this theory starting from the definition of K3 surfaces and going as far as the global Torelli theorem for irreducible holomorphic symplectic manifolds as recently proved by M. Verbitsky. For many years the last open question of Weil’s programme was that of the geometric type of the moduli spaces of polarised K3 surfaces. We explain how this problem has been solved. Our method uses algebraic geometry, modular forms and Borcherds automorphic products. We collect and discuss the relevant facts from the theory of modular forms with respect to the orthogonal group O(2,n). We also give a detailed description of quasi pull-back of automorphic Borcherds products. This part contains previously unpublished results. Contents 1 Introduction 2 2 Periods of K3 surfaces and the Torelli theorem 4 3 Irreducible symplectic manifolds 15 4 Projective models 24 arXiv:1012.4155v2 [math.AG] 26 May 2011 5 Compactifications 26 6 Modular forms and Kodaira dimension 39 7 Orthogonal groups and reflections 46 8 The quasi pull-back of modular forms 51 9 Arithmetic of root systems 59 1 1 Introduction The history of K3 surfaces goes back to classical algebraic geometry. In modern complex algebraic geometry a K3 surface is a compact complex surface S whose canonical bundle is trivial, i.e. -
Intersection Theory
APPENDIX A Intersection Theory In this appendix we will outline the generalization of intersection theory and the Riemann-Roch theorem to nonsingular projective varieties of any dimension. To motivate the discussion, let us look at the case of curves and surfaces, and then see what needs to be generalized. For a divisor D on a curve X, leaving out the contribution of Serre duality, we can write the Riemann-Roch theorem (IV, 1.3) as x(.!Z'(D)) = deg D + 1 - g, where xis the Euler characteristic (III, Ex. 5.1). On a surface, we can write the Riemann-Roch theorem (V, 1.6) as 1 x(!l'(D)) = 2 D.(D - K) + 1 + Pa· In each case, on the left-hand side we have something involving cohomol ogy groups of the sheaf !l'(D), while on the right-hand side we have some numerical data involving the divisor D, the canonical divisor K, and some invariants of the variety X. Of course the ultimate aim of a Riemann-Roch type theorem is to compute the dimension of the linear system IDI or of lnDI for large n (II, Ex. 7.6). This is achieved by combining a formula for x(!l'(D)) with some vanishing theorems for Hi(X,!l'(D)) fori > 0, such as the theorems of Serre (III, 5.2) or Kodaira (III, 7.15). We will now generalize these results so as to give an expression for x(!l'(D)) on a nonsingular projective variety X of any dimension. And while we are at it, with no extra effort we get a formula for x(t&"), where @" is any coherent locally free sheaf. -
2020-2021 Annual Report
Institute for Computational and Experimental Research in Mathematics Annual Report May 1, 2020 – April 30, 2021 Brendan Hassett, Director, PI Mathew Borton, IT Director Ruth Crane, Assistant Director and Chief of Staff Juliet Duyster, Assistant Director Finance and Administration Sigal Gottlieb, Deputy Director Jeffrey Hoffstein, Consulting Associate Director Caroline Klivans, Deputy Director Benoit Pausader, co-PI Jill Pipher, Consulting Director Emerita, co-PI Kavita Ramanan, Associate Director, co-PI Bjorn Sandstede, Associate Director, co-PI Ulrica Wilson, Associate Director for Diversity and Outreach Table of Contents Mission ........................................................................................................................................... 5 Annual Report for 2020-2021 ........................................................................................................ 5 Core Programs and Events ............................................................................................................ 5 Participant Summaries by Program Type ..................................................................................... 7 ICERM Funded Participants ................................................................................................................. 7 ICERM Funded Speakers ...................................................................................................................... 9 All Speakers (ICERM funded and Non-ICERM funded) ................................................................ -
Arxiv:Math/9809023V1 [Math.AG] 5 Sep 1998 .W a That Say We 0
UNIFORMITY OF STABLY INTEGRAL POINTS ON PRINCIPALLY POLARIZED ABELIAN VARIETIES OF DIMENSION ≤ 2 DAN ABRAMOVICH AND KENJI MATSUKI Abstract. The purpose of this paper is to prove, assuming that the conjecture of Lang and Vojta holds true, that there is a uniform bound on the number of stably integral points in the complement of the theta divisor on a principally polarized abelian surface defined over a number field. Most of our argument works in arbitrary dimension and the restriction on the dimension ≤ 2 is used only at the last step, where we apply Pacelli’s stronger uniformity results for elliptic curves. Preliminary version, July 13, 2021. 0. Introduction 0.1. The conjecture of Lang and Vojta. Let X be a variety over a field of characteristic 0. We say that X is a variety of logarithmic general type, if there exists a desingularization X˜ → X, and a projective embedding X˜ ⊂ Y where D = Y X˜ is a divisor of normal crossings, such that the invertible sheaf ωY (D) is big. We note first that this peoperty is independent of the choices of X˜ and Y , and that it is a proper birational invariant, namely, if X′ → X is a proper birational morphism (or an inverse of such) then X is of logarithmic general type if and only if X′ is. Now let X be a variety of logarithmic general type defined over a number field K. Let S be a finite set of places in K and let OK,S ⊂ K be the ring of S-integers. Fix a model X of X over OK,S. -
Advanced Lectures in Mathematics (ALM)
Advanced Lectures in Mathematics (ALM) ALM 1: Superstring Theory ALM 2: Asymptotic Theory in Probability and Statistics with Applications ALM 3: Computational Conformal Geometry ALM 4: Variational Principles for Discrete Surfaces ALM 6: Geometry, Analysis and Topology of Discrete Groups ALM 7: Handbook of Geometric Analysis, No. 1 ALM 8: Recent Developments in Algebra and Related Areas ALM 9: Automorphic Forms and the Langlands Program ALM 10: Trends in Partial Differential Equations ALM 11: Recent Advances in Geometric Analysis ALM 12: Cohomology of Groups and Algebraic K-theory ALM 13: Handbook of Geometric Analysis, No. 2 ALM 14: Handbook of Geometric Analysis, No. 3 ALM 15: An Introduction to Groups and Lattices: Finite Groups and Positive Definite Rational Lattices ALM 16: Transformation Groups and Moduli Spaces of Curves ALM 17: Geometry and Analysis, No. 1 ALM 18: Geometry and Analysis, No. 2 ALM 19: Arithmetic Geometry and Automorphic Forms ALM 20: Surveys in Geometric Analysis and Relativity ALM 21: Advances in Geometric Analysis ALM 22: Differential Geometry: Under the Influence of S.-S. Chern ALM 23: Recent Developments in Geometry and Analysis ALM 24: Handbook of Moduli, Volume I ALM 25: Handbook of Moduli, Volume II ALM 26: Handbook of Moduli, Volume III Advanced Lectures in Mathematics Volume XXV Handbook of Moduli Volume II edited by Gavril Farkas · Ian Morrison International Press 浧䷘㟨十⒉䓗䯍 www.intlpress.com HIGHER EDUCATION PRESS Advanced Lectures in Mathematics, Volume XXV Handbook of Moduli, Volume II Volume Editors: Gavril Farkas (Humboldt-Universität, Berlin) Ian Morrison (Fordham University, New York) 2010 Mathematics Subject Classification. Primary: 14D20. -
1875–2012 Dr. Jan E. Wynn
HISTORY OF THE DEPARTMENT OF MATHEMATICS BRIGHAM YOUNG UNIVERSITY 1875–2012 DR. LYNN E. GARNER DR. GURCHARAN S. GILL DR. JAN E. WYNN Copyright © 2013, Department of Mathematics, Brigham Young University All rights reserved 2 Foreword In August 2012, the leadership of the Department of Mathematics of Brigham Young University requested the authors to compose a history of the department. The history that we had all heard was that the department had come into being in 1954, formed from the Physics Department, and with a physicist as the first chairman. This turned out to be partially true, in that the Department of Mathematics had been chaired by physicists until 1958, but it was referred to in the University Catalog as a department as early as 1904 and the first chairman was appointed in 1906. The authors were also part of the history of the department as professors of mathematics: Gurcharan S. Gill 1960–1999 Lynn E. Garner 1963–2007 Jan E. Wynn 1966–2000 Dr. Gill (1956–1958) and Dr. Garner (1960–1962) were also students in the department and hold B. S. degrees in Mathematics from BYU. We decided to address the history of the department by dividing it into three eras of quite different characteristics. The first era (1875–1978): Early development of the department as an entity, focusing on rapid growth during the administration of Kenneth L. Hillam as chairman. The second era (1978–1990): Efforts to bring the department in line with national standards in the mathematics community and to establish research capabilities, during the administration of Peter L. -
Curriculum Vitae: Brendan Hassett
Curriculum Vitae: Brendan Hassett Brown University brendan [email protected] Institute for Computational and Experimental Research in Mathematics 121 South Main Street, 11th Floor, Box E Providence, RI 02903 USA 401 863 7010 Department of Mathematics Box 1917 151 Thayer Street Providence, Rhode Island 02912 USA 401 863 7961 Positions Director, Institute for Computational and Experimental Research in Mathemat- ics, Brown University, from July 2016 Professor of Mathematics, from July 2015 Milton Brockett Porter Professor, Rice University, July 2013 to June 2015 Chair, Department of Mathematics, July 2009 to June 2014 Professor of Mathematics, July 2006 to June 2015 Associate Professor of Mathematics, July 2003 to June 2006 Assistant Professor of Mathematics, July 2000 to June 2003 Professeur Invit´e,Universit´eParis-Sud, Orsay, March to April 2005 Visiting Scholar, Institute of Mathematical Sciences, Chinese University of Hong Kong, August 2000 to July 2001 Dickson Instructor of Mathematics, University of Chicago, October 1996 to September 2000 Visitor at the Institut Mittag-Leffler, Stockholm, January to March 1997 Education Harvard University, M.A., 1994, and Ph.D., 1996 (supervised by Joe Harris) Yale College, B.A. in mathematics, summa cum laude, 1992 Awards Fellow of the American Mathematical Society, 2014 Charles W. Duncan Jr. Achievement Award for Outstanding Faculty, Rice Uni- versity, 2009 Grants and Fellowships Simons Foundation Award 815891: September 1, 2021{August 31, 2023; Simons Bridge for Postdoctoral Fellowships at ICERM -
Arxiv:1506.07513V2 [Math.AG] 2 Aug 2016 Flggnrltp,Adamorphism a and Type, General Log of Olo Hspprt Etepofo H Olwn Theorem: Following the of Pa Proof of 1.1
A FIBERED POWER THEOREM FOR PAIRS OF LOG GENERAL TYPE KENNETH ASCHER AND AMOS TURCHET Abstract. Let f : (X,D) → B be a stable family with log canonical general fiber. We prove that, after a birational modification of the base B → B, there is a morphism from a high fibered power of the family to a pair of log general type. If in addition the general fiber is openly canonical, then there is a morphisme from a high fibered power of the original family to a pair openly of log general type. 1. Introduction We work over an algebraically closed field of characteristic 0. Analyzing the geometry of fibered powers of families of varieties has been pivotal in showing that well known conjectures in Diophantine geometry imply uniform bounded- ness of rational points on algebraic varieties of general type. In 1997, Caporaso, Harris, and Mazur, show in their celebrated paper [CHM97], that various versions of Lang’s conjecture imply uniform boundedness of rational points on curves of general type. More precisely, they show that, assuming Lang’s conjecture, for every number field K and integer g ≥ 2, there exists an integer B(K,g) such that no smooth curve of genus g ≥ 2 defined over K has more than B(K,g) rational points. Similar statements were proven for the case of surfaces of general type by Hassett [Has96], and eventually all positive dimensional varieties of general type in a series of two papers by Abramovich and Abramovich-Voloch ([Abr97a] and [AV96]). The essence of these papers, is a purely algebro-geometric statement: the proof of a ”fibered power theorem”, which analyzes the behavior of families of varieties of general type.