English

On the quasi-isometric classification of permutational wreath products

Group Theory 2025-03-19 v2

Abstract

In this article, we initiate the study of the large-scale geometry of permutational wreath products of the form FH/NHF\wr_{H/N}H, where HH is finitely presented and where NN is a normal subgroup of HH satisfying a certain assumption of non coarse separation. The main result is a complete classification of such permutational wreath products up to quasi-isometry, building up on previous works from Genevois and Tessera. For instance, we show that, for dk2d\ge k\ge 2, ZnZkZd\mathbb{Z}_{n}\wr_{\mathbb{Z}^{k}} \mathbb{Z}^d and ZmZkZd\mathbb{Z}_{m}\wr_{\mathbb{Z}^{k}}\mathbb{Z}^d are quasi-isometric if and only if nn and mm are powers of a common number. We also discuss biLipschitz equivalences between permutational wreath products, their scaling groups, as well as the quasi-isometric classification of other halo products built out of such permutational lamplighters.

Keywords

Cite

@article{arxiv.2409.20159,
  title  = {On the quasi-isometric classification of permutational wreath products},
  author = {Vincent Dumoncel},
  journal= {arXiv preprint arXiv:2409.20159},
  year   = {2025}
}

Comments

v1: 58 pages, comments are welcome! v2: Minor changes, some typos corrected and references updated