English

Isoperimetric profiles of lamplighter-like groups

Group Theory 2026-04-17 v2 Geometric Topology Metric Geometry

Abstract

Given a finitely generated amenable group HH satisfying some mild assumptions, we relate isoperimetric profiles of the lampshuffler group Shuffler(H)=FSym(H)H\mathsf{Shuffler}(H)=\mathsf{FSym}(H)\rtimes H to those of HH. Our results are sharp for all exponential growth groups for which isoperimetric profiles are known, including Brieussel-Zheng groups. This refines previous estimates obtained by Erschler and Zheng and by Saloff-Coste and Zheng. The most difficult part is to find an optimal upper bound, and our strategy consists in finding suitable lamplighter subgraphs in lampshufflers. This novelty applies more generally for many examples of halo products, a class of groups introduced recently by Genevois and Tessera as a natural generalisation of wreath products. Lastly, we also give applications of our estimates on isoperimetric profiles to the existence problem of regular maps between such groups.

Keywords

Cite

@article{arxiv.2506.13235,
  title  = {Isoperimetric profiles of lamplighter-like groups},
  author = {Corentin Correia and Vincent Dumoncel},
  journal= {arXiv preprint arXiv:2506.13235},
  year   = {2026}
}

Comments

49 pages (with appendix)