Horospherical coordinates

This paper is organized as follows: In the preliminary Section 2 we state well-known facts about the complex hyperbolic plane, its boundary, horospherical coordinates, and the Cygan metric. In Section 3 we prove the Ptolemaean inequality (Theorem 3.1), and finally in Section 4 we prove Ptolemaeus’ theorem.

13p danhdanh27 07-01-2019 15 2   Download