English

${\rm CAT(0)}$ cube complexes are determined by their boundary cross ratio

Geometric Topology 2022-01-28 v4 Group Theory

Abstract

We introduce a Z\mathbb{Z}-valued cross ratio on Roller boundaries of CAT(0){\rm CAT(0)} cube complexes. We motivate its relevance by showing that every cross-ratio preserving bijection of Roller boundaries uniquely extends to a cubical isomorphism. Our results are strikingly general and even apply to infinite dimensional, locally infinite cube complexes with trivial automorphism group.

Keywords

Cite

@article{arxiv.1805.08478,
  title  = {${\rm CAT(0)}$ cube complexes are determined by their boundary cross ratio},
  author = {Jonas Beyrer and Elia Fioravanti and Merlin Incerti-Medici},
  journal= {arXiv preprint arXiv:1805.08478},
  year   = {2022}
}

Comments

19 pages, 3 figures. Final version, to appear on Groups Geom Dyn

R2 v1 2026-06-23T02:03:51.660Z