Less than continuum many translates of a compact nullset may cover any infinite profinite group

Profinite properties of RAAGs and special groups

In this paper we prove that RAAGs are distinguished from each other by their pro-$p$ completions for any choice of prime $p$, and that RACGs are distinguished from each other by their pro-2 completions. We also give a new proof that hyperbolic virtually special groups are good in the sense of Serre. Furthermore we give an example of a property of the underlying graph of a RAAG that translates to a property of the profinite completion.

Profinite 完备化与上同调跳跃轨迹

Profinite completions and cohomology jump loci

本文证明 profinite 完备化在特定假设下决定 CW 复形的上同调跳跃轨迹及言语子群分次商，并应用于超平面排列，揭示其不区分算术 Zariski 对且不决定排列群。