English

Landing rays and ray Cannon-Thurston maps

Geometric Topology 2025-03-25 v1 Group Theory

Abstract

For a hyperbolic subgroup H of a hyperbolic group G, we describe sufficient criteria to guarantee the following. 1) Geodesic rays in H starting at the identity land at a unique point of the boundary of G. 2)The inclusion of H into G does not extend continuously to the boundary. As a consequence we obtain sufficient conditions that provide a mechanism to guarantee the non-existence of Cannon-Thurston maps. One such criterion we use extensively is an adaptation of a property proven by Jeon, Kapovich, Leininger and Ohshika. As a consequence we describe a number of classes of examples demonstrating the non-existence of Cannon-Thurston maps. We recover, in the process, a simple counter-example lying at the heart of Baker and Riley's examples.

Keywords

Cite

@article{arxiv.2503.17815,
  title  = {Landing rays and ray Cannon-Thurston maps},
  author = {Rakesh Halder and Mahan Mj and Pranab Sardar},
  journal= {arXiv preprint arXiv:2503.17815},
  year   = {2025}
}

Comments

45 pgs. No figures

R2 v1 2026-06-28T22:30:57.370Z