English

Automorphism groups of Boolean powers with ample generics

Rings and Algebras 2025-09-25 v1 Group Theory Logic

Abstract

Let AA be a finite non-abelian simple Mal'cev algebra, such as for example a finite simple non-abelian group or a finite simple non-zero ring. We show that the automorphism group of a filtered Boolean power of AA by the countable atomless Boolean algebra AA has ample generics. This uses the decomposition of that automorphism group as a semidirect product of a certain closure of a Boolean power of the automorphism group of AA by BB and the stabiliser of finitely many points in the homeomorphism group Homeo2ω2^\omega of the Cantor space 2ω2^\omega by the authors. As an intermediate step, we show that pointwise stabilisers in Homeo2ω2^\omega have ample generics, which extends the result of Kwiatkowska that Homeo2ω2^\omega has ample generics.

Keywords

Cite

@article{arxiv.2509.20121,
  title  = {Automorphism groups of Boolean powers with ample generics},
  author = {Peter Mayr and Nik Ruškuc},
  journal= {arXiv preprint arXiv:2509.20121},
  year   = {2025}
}
R2 v1 2026-07-01T05:54:09.627Z