Jürgen Jost

Nonpositive Curvature: Geometric and Analytic Aspects

• Broschiertes Buch

Produktbeschreibung

The present book contains the lecture notes from a "Nachdiplomvorlesung", a topics course adressed to Ph. D. students, at the ETH ZUrich during the winter term 95/96. Consequently, these notes are arranged according to the requirements of organizing the material for oral exposition, and the level of difficulty and the exposition were adjusted to the audience in Zurich. The aim of the course was to introduce some geometric and analytic concepts that have been found useful in advancing our understanding of spaces of nonpos itive curvature. In particular in recent years, it has been realized that often it is useful for a systematic understanding not to restrict the attention to Riemannian manifolds only, but to consider more general classes of metric spaces of generalized nonpositive curvature. The basic idea is to isolate a property that on one hand can be formulated solely in terms of the distance function and on the other hand is characteristic of nonpositive sectional curvature on a Riemannian manifold, and then to take this property as an axiom for defining a metric space of nonposi tive curvature. Such constructions have been put forward by Wald, Alexandrov, Busemann, and others, and they will be systematically explored in Chapter 2. Our focus and treatment will often be different from the existing literature. In the first Chapter, we consider several classes of examples of Riemannian manifolds of nonpositive curvature, and we explain how conditions about nonpos itivity or negativity of curvature can be exploited in various geometric contexts.

Produktdetails

• Lectures in Mathematics. ETH Zürich
• Verlag: Birkhäuser / Birkhäuser Basel / Springer, Basel
• Artikelnr. des Verlages: 978-3-7643-5736-8
• 1997.
• Seitenzahl: 120
• Erscheinungstermin: 1. Mai 1997
• Englisch
• Abmessung: 244mm x 170mm x 7mm
• Gewicht: 244g
• ISBN-13: 9783764357368
• ISBN-10: 3764357363
• Artikelnr.: 27488764

Autorenporträt

Jürgen Jost studierte von 1975 bis 1980 Mathematik, Physik, Volkswirtschaftslehre und Philosophie an der Universität Bonn. Er promovierte 1980 in der Mathematik und wurde nach verschiedenen internationalen Forschungsaufenthalten 1984 als Professor für Mathematik an die Ruhruniversität Bochum und 1996 als Direktor an das neu zu gründende Max-Planck-Institut für Mathematik in den Naturwissenschaften in Leipzig berufen. Er ist auch Honorarprofessor an der Universität Leipzig und externes Fakultätsmitglied des Santa Fe Institute for the Sciences of Complexity in den USA. 1993 erhielt er den Gottfried-Wilhelm-Leibniz-Preis der DFG und 2010 einen Advanced Grant des European Research Council. Er ist Autor von mehr als 20 Forschungsmonographien und Lehrbüchern und von über 400 wissenschaftlichen Fachpublikationen. In seinen Forschungen verbindet er eine Vielzahl von mathematischen Disziplinen und Methoden mit einer allgemeinen Theorie komplexer Systeme und vielfältigen Anwendungen in der mathematischen und theoretischen Biologie und Neurobiologie.

Inhaltsangabe

1 Introduction.- 1.1 Examples of Riemannian manifolds of negative or nonpositive sectional curvature.- 1.2 Mordell and Shafarevitch type problems.- 1.3 Geometric superrigidity.- 2 Spaces of nonpositive curvature.- 2.1 Local properties of Riemannian manifolds of nonpositive sectional curvature.- 2.2 Nonpositive curvature in the sense of Busemann.- 2.3 Nonpositive curvature in the sense of Alexandrov.- 3 Convex functions and centers of mass.- 3.1 Minimizers of convex functions.- 3.2 Centers of mass.- 3.3 Convex hulls.- 4 Generalized harmonic maps.- 4.1 The definition of generalized harmonic maps.- 4.2 Minimizers of generalized energy functional.- 5 Bochner-Matsushima type identities for harmonic maps and rigidity theorems.- 5.1 The Bochner formula for harmonic one-forms and harmonic maps.- 5.2 A Matsushima type formula for harmonic maps.- 5.3 Geometrie superrigidity.

Rezensionen

"Recollects some basic properties as well as some fairly advanced results [which] is done with a spirit that allows one to understand that, even though the study of such manifolds has important differences from the flat case, some techniques come from the very elementary Euclidean geometry." --Mathematical Reviews