Complex cross--ratios and the Ptolemaean inequality

Abstract

We use Korányi--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.

6 pages

References in corpus (1)

• Moebius structures and Ptolemy spaces: boundary at infinity of complex hyperbolic spaces

Cited by in corpus (1)

• Cross ratios and the Ptolemaean inequality in boundaries of symmetric spaces of rank 1