Archiv der Mathematik

, 93:487

An alternative proof of Berg and Nikolaev’s characterization of CAT(0)-spaces via quadrilateral inequality

Article

DOI: 10.1007/s00013-009-0057-9

Cite this article as:
Sato, T. Arch. Math. (2009) 93: 487. doi:10.1007/s00013-009-0057-9

Abstract

We give a short alternative proof of Berg and Nikolaev’s recent theorem on a characterization of CAT(0)-spaces via the quadrilateral inequality.

Mathematics Subject Classification (2000)

53C21 

Keywords

CAT(0)-space Quadrilateral inequality 

Copyright information

© Birkhäuser Verlag Basel/Switzerland 2009

Authors and Affiliations

  1. 1.Department of Mathematics, Faculty of ScienceKyoto UniversityKyotoJapan