## Nihonkai Mathematical Journal

### The Alexandrov-Toponogov comparison theorem for radial curvature

#### Abstract

We discuss the Alexandrov-Toponogov comparison theorem under the conditions of radial curvature of a pointed manifold $(M,o)$ with reference surface of revolution $(\widetilde M, \tilde o)$. There are two obstructions to make the comparison theorem for a triangle one of whose vertices is a base point $o$. One is the cut points of another vertex $\tilde p \not=\tilde o$ of a comparison triangle in $\widetilde M$. The other is the cut points of the base point $o$ in $M$. We find a condition under which the comparison theorem is valid for any geodesic triangle with a vertex at $o$ in $M$.

#### Article information

Source
Nihonkai Math. J., Volume 24, Number 2 (2013), 57-91.

Dates
First available in Project Euclid: 24 February 2014

https://projecteuclid.org/euclid.nihmj/1393273815

Mathematical Reviews number (MathSciNet)
MR3178500

Zentralblatt MATH identifier
1296.53067

#### Citation

Innami, Nobuhiro; Shiohama, Katsuhiro; Uneme, Yuya. The Alexandrov-Toponogov comparison theorem for radial curvature. Nihonkai Math. J. 24 (2013), no. 2, 57--91. https://projecteuclid.org/euclid.nihmj/1393273815

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