English

Coboundary expansion and Gromov hyperbolicity

Geometric Topology 2023-09-13 v1 Group Theory

Abstract

We prove that if a compact nn-manifold admits a sequence of residual covers that form a coboundary expander in dimension n2n-2, then the manifold has Gromov-hyperbolic fundamental group. In particular, residual sequences of covers of non-hyperbolic compact connected irreducible 3-manifolds are not 1-coboundary expanders.

Keywords

Cite

@article{arxiv.2309.06215,
  title  = {Coboundary expansion and Gromov hyperbolicity},
  author = {Dawid Kielak and Piotr W. Nowak},
  journal= {arXiv preprint arXiv:2309.06215},
  year   = {2023}
}
R2 v1 2026-06-28T12:19:12.500Z