English

Complex cross--ratios and the Ptolemaean inequality

Differential Geometry 2012-07-24 v1 Metric Geometry

Abstract

We use Kor\'anyi--Reimann complex cross--ratios to prove the Ptolemaean inequality and the Theorem of Ptolemaeus in the setting of the boundary of complex hyperbolic space and the first Heisenberg group.

Cite

@article{arxiv.1207.5114,
  title  = {Complex cross--ratios and the Ptolemaean inequality},
  author = {Ioannis D. Platis},
  journal= {arXiv preprint arXiv:1207.5114},
  year   = {2012}
}

Comments

6 pages

R2 v1 2026-06-21T21:39:25.497Z