English

Rigidity on horocycles and hypercycles

Geometric Topology 2024-05-29 v1

Abstract

We show that a bijection f:H2H2f:\mathbb{H}^2\rightarrow\mathbb{H}^2 of the hyperbolic plane that sends horocycles to horocycles (respectively hypercycles to hypercycles) is an isometry. This extends a previous result of J. Jeffers on geodesics to all curves with constant curvature in H2\mathbb{H}^2. We go beyond by showing that every abstract automorphism of the geodesic graph (respectively horocycles and hypercycles graphs) is induced by an earthquake map (respectively an isometry) of H2\mathbb{H}^2. This shadowed the difference between the geometry of geodesics and that of horocycles/hypercycles.

Keywords

Cite

@article{arxiv.2405.17598,
  title  = {Rigidity on horocycles and hypercycles},
  author = {Cheikh Lo and Abdoul Karim Sane},
  journal= {arXiv preprint arXiv:2405.17598},
  year   = {2024}
}
R2 v1 2026-06-28T16:42:50.945Z