Existence and Regularity of Branched Minimal Submanifolds

Total Page:16

File Type:pdf, Size:1020Kb

Existence and Regularity of Branched Minimal Submanifolds EXISTENCE AND REGULARITY OF BRANCHED MINIMAL SUBMANIFOLDS A DISSERTATION SUBMITTED TO THE DEPARTMENT OF MATHEMATICS AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Brian Krummel August 2011 © 2011 by Brian James Krummel. All Rights Reserved. Re-distributed by Stanford University under license with the author. This work is licensed under a Creative Commons Attribution- Noncommercial 3.0 United States License. http://creativecommons.org/licenses/by-nc/3.0/us/ This dissertation is online at: http://purl.stanford.edu/rc085mz1473 ii I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Leon Simon, Primary Adviser I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Richard Schoen I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Brian White Approved for the Stanford University Committee on Graduate Studies. Patricia J. Gumport, Vice Provost Graduate Education This signature page was generated electronically upon submission of this dissertation in electronic format. An original signed hard copy of the signature page is on file in University Archives. iii Abstract We consider two-valued solutions to elliptic problems, which arise from the study branched minimal submanifolds. Simon and Wickramasekera constructed in [10] examples of two-valued solutions to the Dirichlet problem for the minimal surface ˘2 n−2 equation on the cylinder C = B1 (0) × R with H¨oldercontinuity estimates on the gradient assuming the boundary data satisfies a symmetry condition. However, their method was specific to the minimal surface equation. We generalize Simon and Wickramasekera's result to an existence theorems for a more general class elliptic equations and for a class of elliptic systems with small data. In particular, we extend Simon and Wickramasekera's result to the minimal surface system. Our approach uses techniques for elliptic differential equations such as the Leray-Schauder theory and contraction mapping principle, which have the advantage of applying in more general contexts than codimension 1 minimal surfaces. We also show that for two- valued solutions to elliptic equations with real analytic data, the branch set of their graphs are real analytic (n − 2)-dimensional submanifolds. This is a consequence of using the Schauder estimate for two-valued functions and a technique involving majorants due to Friedman [2] to inductively get estimates on the derivatives of the two-valued solutions. iv Acknowledgments I am grateful for my advisor Leon Simon, whose ideas and encouragement were in- valuable to my dissertation work. Leon's insightful way of looking at mathematics has had a positive influence on me as a mathematician. I consider myself fortunate to have been his student. I also thank Rick Schoen, Brian White, Rafe Mazzeo, and Simon Brendle for tak- ing time to meet with me to discuss mathematics throughout my time at Stanford. Their ideas have often been interesting and helpful in my work. In particular, I thank Rick Schoen, Brian White, and Rafe Mazzeo for being on my dissertation committee and Simon Brendle for providing financial support for my quarter spent at Cambridge. I appreciate Neshan Wickramasekera showing his interest in my research and tak- ing time to talk with me about it while I was visiting Cambridge. Finally I am thankful to my friends and family for their support and interest in my academic endeavors. In particular, I am grateful to my parents for teaching me the value of education from a young age and for their encouragement during my graduate work. v Contents Abstract iv Acknowledgments v 1 Introduction and Statement of Main Results 1 1.1 Notation . 1 1.2 Two-valued functions . 2 1.3 The function spaces Vk and Vk,µ ..................... 10 1.4 Minimal submanifolds . 18 1.5 Existence and regularity theorems . 21 2 Elliptic theory for two-valued functions 28 2.1 Overview . 28 2.2 Maximum principles . 29 2.3 Schauder estimates . 35 2.4 Global estimates . 45 2.5 H¨oldercontinuity estimates . 50 3 Existence theorems 60 3.1 Overview . 60 3.2 Poisson equation . 60 3.3 Elliptic systems . 68 3.4 Elliptic equations . 73 vi 4 Regularity theorems 88 4.1 C1,µ regularity of C1 solutions . 88 4.2 Smoothness of two-valued solutions . 112 4.3 Bounding gγ ................................ 118 i 4.4 Bounding the H¨oldercoefficient of fγ . 123 4.5 Analyticity of two-valued solutions . 129 Bibliography 133 vii Chapter 1 Introduction and Statement of Main Results 1.1 Notation We shall adopt the following notation and conventions throughout this thesis. n ≥ 3 is a fixed integer. m m BR (X0) denotes the closed ball of radius R centered at X0 in R . ˘m m BR (X0) denotes the open ball of radius R centered at X0 in R . n ˘ ˘n BR(X0) = BR(0), BR(X0) = BR(X0). ˘2 n−2 n C = B1 (0) × R denotes an open cylinder in R . 2 n−2 X = (x; y) denotes a point in C, where x 2 B1 (0) and y 2 R . We identify x with the point reiθ in C, where r 2 [0; 1] and θ 2 R. 1 CHAPTER 1. INTRODUCTION AND STATEMENT OF MAIN RESULTS 2 iθ iθ+iφ Rφ denotes the n × n matrix such that Rφ(re ; y) = (re ; y). We write 0 1 cos φ − sin φ 0 0 ··· 0 B C Bsin φ cos φ 0 0 ··· 0C B C B 0 0 1 0 ··· 0C i B C Rφ = (R )i;j=1;:::;n = B C j B 0 0 0 1 ··· 0C B C B . .C B . .. .C @ A 0 0 0 0 ··· 1 j where Ri denotes the entry in the i-th row and j-th column of Rφ. Rm×n denotes the space of m × n real matrices. Hk denotes the k-th dimensional Hausdorff measure. Ln denotes the Lebesgue measure in Rn. 1.2 Two-valued functions Let Ω be a domain in Rn. Given an integer q ≥ 2, we say u is a q-valued function m on Ω taking values in R if at each point X 2 Ω, u(X) = fu1(X); : : : ; uq(X)g is an m unordered q-tuple, where uj(X) 2 R [1]. We can define a metric G on the space of unordered q-tuples by q !1=2 X 2 G(u; v) = sup inf juj − vσ(j)j X2Ω σ j=1 for unordered q-tuples u = fu1; : : : uqg and v = fv1; : : : vqg, where σ is a permutation of f1; 2; : : : ; qg. We say a q-valued function u is continuous at X 2 Ω if lim G(u(X); u(Y )) = 0: Y !X CHAPTER 1. INTRODUCTION AND STATEMENT OF MAIN RESULTS 3 We say a q-valued function u from Ω ⊆ Rn to unordered q-tuples in Rm is differentiable at X 2 Ω if for some m × n matrices A1;:::Aq, G(u(X + h); fu (X) + A hg) lim j j = 0; h!0 jhj in which case we say Du(X) = fA1;:::;Aqg is the derivative of u at X. We define k-th order derivatives for integers k ≥ 2 inductively by Dku(X) = D(Dk−1u)(X). For integers k ≥ 0, Ck(Ω; Rm) denotes the space of q-valued functions u on Ω taking values in Rm such that Dju exists and is continuous for 0 ≤ j ≤ k. We say u is H¨oldercontinuous with exponent µ 2 (0; 1] on Ω if G(u(X); u(Y )) [u]µ,Ω = sup µ < 1: (1.1) X;Y 2Ω;X6=Y jX − Y j For k ≥ 0 and µ 2 (0; 1], Ck,µ(Ω; Rm) denotes the space of two-valued functions u 2 Ck(Ω; Rm) such that Dku is H¨oldercontinuous with exponent µ. For Ω ⊆ Rn open, k m k m given k ≥ 0 we let Cc (Ω; R ) denote the space of two-valued functions u 2 C (Ω; R ) such that u = f0; 0g on Ω n Ω0 for some Ω0 ⊂⊂ Ω and given k ≥ 0 and µ 2 (0; 1] we k,µ m k,µ m let Cc (Ω; R ) denote the space of two-valued functions u 2 C (Ω; R ) such that u = f0; 0g on Ω n Ω0 for some Ω0 ⊂⊂ Ω. For Ω ⊆ Rn open, k ≥ 0, and µ 2 (0; 1], we k,µ m k m k,µ 0 m let Cloc (Ω; R ) denote the space of u 2 C (Ω; R ) such that u 2 C (Ω ; R ) for all Ω0 ⊂⊂ Ω. For Ω ⊆ Rn, we let kukC0(Ω) = sup G(u(X); 0) X2Ω for each two-valued function u 2 C0(Ω; Rm), X α kukCk(Ω) = kD ukC0(Ω) jα|≤k for each two-valued function u 2 Ck(Ω; Rm) for k ≥ 1, and X α X α kukCk,µ(Ω) = kD ukC0(Ω) + [D u]µ,Ω jα|≤k jαj=k CHAPTER 1. INTRODUCTION AND STATEMENT OF MAIN RESULTS 4 for each two-valued function u 2 Ck,µ(Ω; Rm) for k ≥ 0 and µ 2 (0; 1). We define a metric on C0(Ω; Rm) by ku − vkC0(Ω) = sup G(u(X); v(X)) X2Ω for two-valued functions u; v 2 C0(Ω; Rm) and we define a metric on Ck(Ω; Rm) for k ≥ 1 by X α α ku − vkCk(Ω) = kD u − D vkC0(Ω) jα|≤k for two-valued functions u; v 2 Ck(Ω; Rm).
Recommended publications
  • Geometric Measure Theory and the Calculus of Variations PROCEEDINGS of SYMPOSIA in PURE MATHEMATICS Volume 44
    http://dx.doi.org/10.1090/pspum/044 Geometric Measure Theory and the Calculus of Variations PROCEEDINGS OF SYMPOSIA IN PURE MATHEMATICS Volume 44 Geometric Measure Theory and the Calculus of Variations William K. Allard and Frederick J. Almgren, Jr., Editors AMERICAN MATHEMATICAL SOCIETY PROVIDENCE, RHODE ISLAND PROCEEDINGS OF THE SUMMER INSTITUTE ON GEOMETRIC MEASURE THEORY AND THE CALCULUS OF VARIATIONS HELD AT HUMBOLDT STATE UNIVERSITY ARCATA, CALIFORNIA JULY 16-AUGUST 3, 1984 with support from the National Science Foundation, Grant DMS-8317890 1980 Mathematics Subject Classification. Primary 49F22, 49F20, 53A10, 53C42; Secondary 49F10, 53C20, 35J65, 58-XX. Library of Congress Cataloging-in-Publication Data Main entry under title: Geometric measure theory and the calculus of variations. (Proceedings of symposia in pure mathematics; v. 44) Includes bibliographies. 1. Geometric measure theory-Addresses, essays, lectures. I. Allard, William K., 1941- II. Almgren, Frederick J. III. Series. QA312.G394 1985 516.3'6 85-18641 ISBN 0-8218-1470-2 (alk. paper) COPYING AND REPRINTING. Individual leaders of this publication, and nonprofit libraries acting for them are permitted to make fair use of the material, such as to copy an article for use in teaching or research. Permission is granted to quote brief passages from this pubUcation in reviews provided the customary acknowledgement of the source is given. Republication, systematic copying, or multiple reproduction of any material in this publication (including abstracts) is permitted only under license from the American Mathematical Society. Requests for such permission should be addressed to the Executive Director, American Mathemat­ ical Society, P.O. Box 6248, Providence, Rhode Island 02940.
    [Show full text]
  • The Geometry of Asymptotically Hyperbolic Manifolds a Dissertation Submitted to the Department of Mathematics and the Committee
    THE GEOMETRY OF ASYMPTOTICALLY HYPERBOLIC MANIFOLDS A DISSERTATION SUBMITTED TO THE DEPARTMENT OF MATHEMATICS AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Otis Chodosh June 2015 © 2015 by Otis Avram Chodosh. All Rights Reserved. Re-distributed by Stanford University under license with the author. This work is licensed under a Creative Commons Attribution- Noncommercial 3.0 United States License. http://creativecommons.org/licenses/by-nc/3.0/us/ This dissertation is online at: http://purl.stanford.edu/mp634xn8004 ii I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Simon Brendle, Primary Adviser I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Michael Eichmair, Co-Adviser I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Leon Simon I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Brian White Approved for the Stanford University Committee on Graduate Studies. Patricia J. Gumport, Vice Provost for Graduate Education This signature page was generated electronically upon submission of this dissertation in electronic format.
    [Show full text]
  • Annual Report for the Fiscal Year
    The Institute for Advanced Study nual Report 1979/80 lis Annual Report has been made possible by a generous grant from the Union Carbide Corporation. The Institute for Advanced Study Annual Report for the Fiscal Year July 1, 1979 - June 30, 1980 The Institute for Advanced Study Princeton, New Jersey 08540 Printed by Princeton University Press Designed by Bruce Campbell It is fundamental to our purpose, and our Extract from the letter addressed by the express desire, that in the appointments to Founders to the Institute's Trustees, the staff and faculty, as well as in the dated June 6, 1930, admission of workers and students, no Newark, New Jersey. account shall be taken, directly or indirectly, of race, religion, or sex. We feel strongly that the spirit characteristic of America at its noblest, above all, the pursuit of higher learning, cannot admit of any conditions as to personnel other than those designed to promote the objects for which this institution is established, and particularly with no regard whatever to accidents of race, creed or sex. 9;2 3f Table of Contents Trustees and Officers 9 Administration 10 The Institute for Advanced Study: Background and Purpose 11 Report of the Chairman 13 Report of the Director 15 Reports of the Schools 21 Publications of the Faculty, Professors Emeriti and Members with Long-term Appointments: A Selection 69 Record of Events, 1979-80 73 Report of the Treasurer 107 Donors 116 Founders Caroline Bamberger Fuld Louis Bamberger Board of Trustees Daniel Bell Howard C. Kauffmann Professor of Sociologi) President Harvard University Exxon Corporation Charles L.
    [Show full text]
  • David Donoho COMMENTARY 52 Cliff Ord J
    ISSN 0002-9920 (print) ISSN 1088-9477 (online) of the American Mathematical Society January 2018 Volume 65, Number 1 JMM 2018 Lecture Sampler page 6 Taking Mathematics to Heart y e n r a page 19 h C th T Ru a Columbus Meeting l i t h i page 90 a W il lia m s r e lk a W ca G Eri u n n a r C a rl ss on l l a d n a R na Da J i ll C . P ip her s e v e N ré F And e d e r i c o A rd ila s n e k c i M . E d al Ron Notices of the American Mathematical Society January 2018 FEATURED 6684 19 26 29 JMM 2018 Lecture Taking Mathematics to Graduate Student Section Sampler Heart Interview with Sharon Arroyo Conducted by Melinda Lanius Talithia Williams, Gunnar Carlsson, Alfi o Quarteroni Jill C. Pipher, Federico Ardila, Ruth WHAT IS...an Acylindrical Group Action? Charney, Erica Walker, Dana Randall, by omas Koberda André Neves, and Ronald E. Mickens AMS Graduate Student Blog All of us, wherever we are, can celebrate together here in this issue of Notices the San Diego Joint Mathematics Meetings. Our lecture sampler includes for the first time the AMS-MAA-SIAM Hrabowski-Gates-Tapia-McBay Lecture, this year by Talithia Williams on the new PBS series NOVA Wonders. After the sampler, other articles describe modeling the heart, Dürer's unfolding problem (which remains open), gerrymandering after the fall Supreme Court decision, a story for Congress about how geometry has advanced MRI, “My Father André Weil” (2018 is the 20th anniversary of his death), and a profile on Donald Knuth and native script by former Notices Senior Writer and Deputy Editor Allyn Jackson.
    [Show full text]
  • The Existence of Embedded Minimal Hypersurfaces 3
    THE EXISTENCE OF EMBEDDED MINIMAL HYPERSURFACES CAMILLO DE LELLIS AND DOMINIK TASNADY Abstract. We give a shorter proof of the existence of nontrivial closed minimal hypersur- faces in closed smooth (n + 1)–dimensional Riemannian manifolds, a theorem proved first by Pitts for 2 ≤ n ≤ 5 and extended later by Schoen and Simon to any n. 0. Introduction In this paper we give a proof of the following theorem, a natural generalization of the classical existence of nontrivial simple closed geodesics in closed 2–d Riemannian manifolds. Theorem 0.1. Let M be an (n+1)-dimensional smooth closed Riemannian manifold. Then there is a nontrivial embedded minimal hypersurface Σ ⊂ M without boundary with a singular set Sing Σ of Hausdorff dimension at most n − 7. More precisely, Σ is a closed set of finite Hn–measure and Sing Σ ⊂ Σ is the smallest closed set S such that M \ S is a smooth embedded hypersurface (Σ \ Sing Σ is in fact analytic if M is analytic). In this paper smooth will always mean C∞. In fact, the result remains true for any C4 Riemannian manifold M, Σ then will be of class C2 (see [19]). Moreover Σ\Sing Σ ω = 0 for any exact n–form on M. The case 2 ≤ n ≤ 5 was proved by Pitts inR his groundbreaking monograph [16], an outstanding contribution which triggered all the subsequent research in the topic. The general case was proved by Schoen and Simon in [19], building heavily upon the work of Pitts. The monograph [16] can be ideally split into two parts.
    [Show full text]
  • Arxiv:1904.02289V1 [Math.DG]
    Stationary one-sided area-minimizing hypersurfaces with isolated singularities Zhenhua Liu Dedicated to Xunjing Wei Abstract. We extend the results of Hardt and Simon in [8] to prove that isolated singularities of stationary one-sided area-minimizing hypersurfaces can be locally perturbed away on the side that they are minimizing. 1. Introduction Area-minimizing hypersurfaces in n + 1-dimensional manifolds M n+1 are known to be smooth outside a set of Hausdorff dimension at most n − 7 ([7]). However, little is known about the geometry of the singular sets. In this regard, the best results to date are the structure theory of area-minimizing hypersurfaces with isolated singularities developed by Robert Hardt and Leon Simon in [16] and [8]. Roughly speaking, they have proved that (i) On any side of an area-minimizing hypercone, all area-minimizing bound- aries confined in that side are smooth and unique up to scalings. (ii) (Based on (i)) On any side of an area-minimizing hypersurface, if the n − 1 boundary of a Plateau problem is close enough to a smooth n − 1 submanifold of the cone, then the solution to the Plateau problem is smooth. arXiv:1904.02289v1 [math.DG] 4 Apr 2019 We will explain the terminologies contained in those statements later. These state- ments basically say that isolated singularities of area-minimizing hypersurfaces be- have as well as one can imagine, in that one can always perturb them away locally in a suitable sense to get smooth objects. In this paper, we extend these results to hypersurfaces that are only area-minimizing on one side.
    [Show full text]
  • Regularity of Capillary Surfaces Over Domains with Corners
    Pacific Journal of Mathematics REGULARITY OF CAPILLARY SURFACES OVER DOMAINS WITH CORNERS LEON M. SIMON Vol. 88, No. 2 April 1980 PACIFIC JOURNAL OF MATHEMATICS Vol. 88, No. 2, 1980 REGULARITY OF CAPILLARY SURFACES OVER DOMAINS WITH CORNERS LEON SIMON Using the usual mathematical model (capillary surface equation with contact angle boundary condition) we discuss regularity of the equilibrium free surface of a fluid in a cylin- drical container in case the container cross-section has corners. It is shown that good regularity holds at a corner if the "corner angle" θ satisfies O<0<τr and θ + 2β>ττ, where 0</3< π/2 is the contact angle between the fluid surface and the container wall. It is known that no regularity holds in case θ + 2β<π, hence only the borderline case θ + 2β = π remains open. We here want to examine the regularity of solutions of capillary surface type equations (subject to contact angle boundary conditions) on domain Ω ciί2 in a neighbourhood of a point of dΩ where there is a corner. To be specific let Ω (as depicted in the diagram) be a region 2 contained in DR = {x e R : | x | < R) (R > 0 given) such that dΩ consists of a circular segment of dDR together with two compact Jordan arcs 7i, 72 such that 7i Π 72 = {0}. 7i, 72 are supposed to be Qua fQΐ some o < a < 1, and to meet at 0 with angle (measured in Ω) θ, 0 < θ < π. We also suppose (without loss of generality, since we can always take a smaller R) that 7* intersects dD0 in a single point for each i = 1, 2, 0 < p < R.
    [Show full text]
  • Arxiv:1102.2999V2 [Math.DG] 30 Jan 2013 N Ftesfgat2-77348-12
    LARGE ISOPERIMETRIC SURFACES IN INITIAL DATA SETS MICHAEL EICHMAIR AND JAN METZGER Abstract. We study the isoperimetric structure of asymptotically flat Riemannian 3–manifolds (M,g) that are C0-asymptotic to Schwarzschild of mass m > 0. Refining an argument due to H. Bray we obtain an ef- fective volume comparison theorem in Schwarzschild. We use it to show that isoperimetric regions exist in (M,g) for all sufficiently large vol- umes, and that they are close to centered coordinate spheres. This im- plies that the volume-preserving stable constant mean curvature spheres constructed by G. Huisken and S.-T. Yau as well as R. Ye as pertur- bations of large centered coordinate spheres minimize area among all competing surfaces that enclose the same volume. This confirms a con- jecture of H. Bray. Our results are consistent with the uniqueness results for volume-preserving stable constant mean curvature surfaces in initial data sets obtained by G. Huisken and S.-T. Yau and strengthened by J. Qing and G. Tian. The additional hypotheses that the surfaces be spherical and far out in the asymptotic region in their results are not necessary in our work. 1. Introduction In this paper we describe completely the large isoperimetric surfaces of asymptotically flat Riemannian 3-manifolds (M, g) that are 0-asymptotic to the Schwarzschild metric of mass m > 0. Such RiemannianC manifolds arise naturally as initial data for the time-symmetric Cauchy problem for arXiv:1102.2999v2 [math.DG] 30 Jan 2013 the Einstein equations in general relativity. For brevity we will refer to such (M, g) as initial data sets in the introduction.
    [Show full text]
  • Mathematics People
    Mathematics People Packard Fellowships Awarded Royal Society of London The David and Lucile Packard Foundation has awarded Elections twenty Fellowships for Science and Engineering for the year Six mathematical scientists are among those elected as new 2002. Among the new fellows are two with links to the fellows of the Royal Society of London for 2003. They are ONALD EDKIW mathematical sciences. R P. F of Stanford Uni- ELEANOR DODSON, University of York; ROGER FLETCHER, versity and RAJESH P. RAO of the University of Washington, University of Dundee; PETER GREEN, University of Bristol; both of whom work in computer science, will each receive JOHN PAPALOIZOU, University of London; and LEON SIMON, a fellowship of $625,000 over five years. Stanford University. DONALD KNUTH, Stanford University, was The fellowships are awarded to researchers in mathe- elected as a foreign member. matics, natural sciences, computer science, and engineering who are in the first three years of a faculty appointment. —From a Royal Society announcement —From a Packard Foundation announcement AMS Menger Prizes at the 2003 ISEF Werschulz Receives Prize for The 2003 Intel-International Science and Engineering Fair Achievement in Information- (ISEF) was held May 11–17 in Cleveland, Ohio. This year marked the fifty-fourth anniversary of the ISEF. More than Based Complexity 1,200 ninth- through twelfth-graders competed in the fair. The participants had qualified by winning competitions in ARTHUR G. WERSCHULZ of Fordham University is the fifth local, regional, and state fairs in the United States or winner of the Prize for Information-Based Complexity. national science fairs abroad.
    [Show full text]
  • Notices of the American Mathematical Society ISSN 0002-9920
    Notices of the American Mathematical Society ISSN 0002-9920 springer.com New and Noteworthy from Springer Lie Sphere How Does One Cut a Triangle? Random Curves nd of the American Mathematical Society Geometry 2 A. Soifer, University of Colorado, Colorado Journeys of a Mathematician EDITION November 2007 Volume 54, Number 10 With Applications Springs, CO, USA N. I. Koblitz , University of Washington, Seattle, to Submanifolds This title demonstrates how diff erent areas WA, USA T. E. Cecil , College of the Holy Cross, of mathematics can be juxtaposed in the These autobiographical memoirs of Neal Worcester, MA, USA solution of any given problem by presenting Koblitz, coinventor of one of the two most an interesting problem, “How does one cut a This book begins with Lie’s construction of the popular forms of encryption and digital triangle?”. By providing analytical proofs and space of spheres, including the fundamental signature, cover many topics besides his own counterexamples, he proves that research is notions of oriented contact, parabolic pencils personal career in mathematics and a collection of mathematical ideas developed of spheres and Lie sphere transformation. The cryptography - travels to the Soviet Union, throughout the course of history. Latin America, Vietnam and elsewhere, link with Euclidean submanifold theory is established via the Legendre map, providing a I very warmly recommend the book and political activism, and academic controversies framework for the study of submanifolds, hope the readers will have pleasure in thinking relating to math education, the C. P. Snow especially those characterized by restrictions about the unsolved problems and will nd new two-culture problem, and mistreatment of on their curvature spheres.
    [Show full text]
  • Calendar of AMS Meetings and Conferences
    Calendar of AMS Meetings and Conferences This calendar lists all meetings which have been approved prior to Mathematical Society in the issue corresponding to that of the Notices the date this issue of Notices was sent to the press. The summer which contains the program of the meeting. Abstracts should be sub­ and annual meetings are joint meetings of the Mathematical Associ­ mitted on special forms which are available in many departments of ation of America and the American Mathematical Society. The meet­ mathematics and from the headquarters office of the Society. Ab­ ing dates which fall rather far in the future are subject to change; this stracts of papers to be presented at the meeting must be received is particularly true of meetings to which no numbers have been as­ at the headquarters of the Society in Providence, Rhode Island, on signed. Programs of the meetings will appear in the issues indicated or before the deadline given below for the meeting. Note that the below. First and supplementary announcements of the meetings will deadline for abstracts for consideration for presentation at special have appeared in earlier issues. sessions is usually three weeks earlier than that specified below. For Abstracts of papers presented at a meeting of the Society are pub­ additional information, consult the meeting announcements and the lished in the journal Abstracts of papers presented to the American list of organizers of special sessions. Meetings Abstract Program Meeting # Date Place Deadline Issue 840 March 18-19, 1988 East Lansing,
    [Show full text]
  • 2006-07 Report from the Mathematical Sciences Research Institute April 2008
    Mathematical Sciences Research Institute Annual Report for 2006-2007 I. Overview of Activities……………………………………………………........ 3 New Developments………………………………………………….. 3 Scientific Program and Workshops………………………………….. 5 Program Highlights………………………………………………….. 11 MSRI Experiences…………………………………………………… 15 II. Programs……………………………………………………………………….. 24 Program Participant List……………………………………………. 25 Participant Summary………………………………………………… 29 Publication List……………………………………………………… 30 III. Postdoctoral Placement……………………………………………………....... 35 IV. Summer Graduate Workshops………………………………………………… 36 Graduate Student Summary…………………………………………. 39 V. Undergraduate Program………………………………………………………… 40 Undergraduate Student Summary……………………………………. 41 VI. External Financial Support…………………………………………………….. 42 VII. Committee Membership……………………………………………………….. 47 VIII. Appendix - Final Reports…………………………………………………......... 49 Programs………………………………………………………………. 49 Geometric Evolution Equations and Related Topics…………... 49 Computational Applications of Algebraic Topology…………... 63 Dynamical Systems…………………………………………….. 70 Workshops……………………………………………………………… 80 Connections for Women: Computational Applications of Algebraic Topology…………………………………………….. 80 MSRI Short Course: An Introduction to Multiscale Methods….. 88 Connections for Women: Geometric Analysis and Nonlinear Partial Differential Equations…………………………... 90 Recent Developments in Numerical Methods and Algorithms for Geometric Evolution Equations….………………… 91 Lectures on String(y) Topology………………………………... 94 Introductory Workshop:
    [Show full text]