Showing 2025Show all
3 papers · 1 filter
math.DS2025
Ample groupoids that are neither almost finite nor purely infinite
Xiaolei Wu, Mengfei Zhao, Xin Ma
We study a question of Matui and varations of it on minimal ample groupoids that are neither almost finite nor purely infinite. We first observe that there are already effective mi…
math.GR2025
Embedding groups into acyclic groups
Martin Palmer, Xiaolei Wu
We show that labelled Thompson groups and twisted Brin--Thompson groups are all acyclic. This allows us to prove several new embedding results for groups. First, every group of typ…
math.GR2025
Some questions related to free-by-cyclic groups and tubular groups
Xiaolei Wu, Shengkui Ye
We prove that a CAT(0) free-by-cyclic tubular group with a single vertex is virtually special, but many of them cannot virtually act freely and cocompactly on CAT(0) cube complexes…