Embedding groups into boundedly acyclic groups
Abstract
We show that the \s{\phi}-labeled Thompson groups and the twisted Brin--Thompson groups are boundedly acyclic. This allows us to prove several new embedding results for groups. First, every group of type embeds quasi-isometrically into a boundedly acyclic group of type that has no proper finite index subgroups. This improves a result of Bridson and a theorem of Fournier-Facio--L\"oh--Moraschini. Second, every group of type embeds quasi-isometrically into a -uniformly perfect group of type . Third, using Belk--Zaremsky's construction of twisted Brin--Thompson groups, we show that every finitely generated group embeds quasi-isometrically into a finitely generated boundedly acyclic simple group. We also partially answer some questions of Brothier and Tanushevski regarding the finiteness property of -labeled Thompson group and .
Cite
@article{arxiv.2407.07703,
title = {Embedding groups into boundedly acyclic groups},
author = {Fan Wu and Xiaolei Wu and Mengfei Zhao and Zixiang Zhou},
journal= {arXiv preprint arXiv:2407.07703},
year = {2025}
}
Comments
Added a new section about l2-invisibility, some other small changes. 42pages. Final version, to appear in J. Lond. Math. Soc