English

$n$-Kazhdan groups and higher spectral expanders

Group Theory 2022-04-11 v2

Abstract

Let Γ\Gamma be a group of type FnF_n and let XX be the nn skeleton of the universal cover of a K(Γ,1)K(\Gamma,1) simplicial complex with finite nn skeleton. We show that if Γ\Gamma is strongly nn-Kazhdan, then for any family of finite index subgroups {Λi}i\{\Lambda_i\}_i, the family of simplicial complexes {Λi\X}i\{\Lambda_i\backslash X\}_i are bounded degree nn-dimensional spectral expanders. Using this we construct new examples of 22 dimensional spectral expanders.

Keywords

Cite

@article{arxiv.2112.09431,
  title  = {$n$-Kazhdan groups and higher spectral expanders},
  author = {Arghya Mondal},
  journal= {arXiv preprint arXiv:2112.09431},
  year   = {2022}
}

Comments

v2: result improved, new result added, introduction rewritten. 14 pages, no figures

R2 v1 2026-06-24T08:21:46.735Z