Projective Cross-Ratio on Hypercomplex Numbers
arXiv:1203.2554 · doi:10.1007/s00006-012-0335-7
Abstract
The paper presents a new cross-ratio of hypercomplex numbers based on projective geometry. We discuss the essential properties of the projective cross-ratio, notably its invariance under Mobius transformations. Applications to the geometry of conic sections and Mobius-invariant metrics on the upper half-plane are also given.