Metric Spaces, Convexity and Nonpositive Curvature (Second edition)
Résumé
This is the second edition of a book which appeared in 2005. The new edition is an expanded and revised version. The book is about metric spaces of nonpositive curvature in the sense of Busemann, that is, metric spaces whose distance function is convex. We have also included a systematic introduction to the theory of geodesics and related matters in metric spaces, as well as a detailed presentation of a few facets of convexity theory that are useful in the study of nonpositive curvature. The exposition starts from first principles and we give full proofs. Examples and applications are spread throughout the book, and they come from hyperbolic geometry, from the theory of Teichmüller spaces and from Hilbert geometry. At the end of each chapter there are historical notes and other notes on further developments.
Mots clés
Convexity
metric space
metric geometry
nonpositive curvature
Busemann geometry
Alexandrov space
global methods
isometries
Busemann space
locally convex space
visual boundary
Busmeann function
horosphere
Minkowski geometry
Menger convexity
Hausdorff metric
hyperbolic geometry
Teichmüller space
Hilbert geometry.
Hilbert geometry