English

On the \v{C}ech cohomology of Morse boundaries

Group Theory 2026-03-25 v2 Geometric Topology

Abstract

We consider cusped hyperbolic nn-manifolds, and compute \v{C}ech cohomology groups of the Morse boundaries of their fundamental groups. In particular, we show that the reduced \v{C}ech cohomology with real coefficients vanishes in dimension at most n3n-3 and does not vanish in dimension n2n-2. A similar result holds for relatively hyperbolic groups with virtually nilpotent peripherals and Bowditch boundary homeomorphic to a sphere; these include all non-uniform lattices in rank1-1 simple Lie groups.

Keywords

Cite

@article{arxiv.2303.15981,
  title  = {On the \v{C}ech cohomology of Morse boundaries},
  author = {Elia Fioravanti and Annette Karrer and Alessandro Sisto and Stefanie Zbinden},
  journal= {arXiv preprint arXiv:2303.15981},
  year   = {2026}
}

Comments

41 pages, 8 figures; minor edits, accepted in Advances in Mathematics