English

Hilbert metric in the unit ball

Metric Geometry 2023-10-31 v3

Abstract

The Hilbert metric between two points x,yx,y in a bounded convex domain GG is defined as the logarithm of the cross-ratio of x,yx,y and the intersection points of the Euclidean line passing through the points x,yx,y and the boundary of the domain. Here, we study this metric in the case of the unit ball Bn\mathbb{B}^n. We present an identity between the Hilbert metric and the hyperbolic metric, give several inequalities for the Hilbert metric, and results related to the inclusion properties of the balls defined in the Hilbert metric. Furthermore, we study the distortion of the Hilbert metric under conformal mappings.

Keywords

Cite

@article{arxiv.2303.03753,
  title  = {Hilbert metric in the unit ball},
  author = {Oona Rainio and Matti Vuorinen},
  journal= {arXiv preprint arXiv:2303.03753},
  year   = {2023}
}

Comments

18 pages, 4 figures

R2 v1 2026-06-28T09:05:08.743Z