English

Is decidability of the Submonoid Membership Problem closed under finite extensions?

Group Theory 2024-05-22 v1 Formal Languages and Automata Theory

Abstract

We show that the rational subset membership problem in GG can be reduced to the submonoid membership problem in G×HG{\times}H where HH is virtually Abelian. We use this to show that there is no algorithm reducing submonoid membership to a finite index subgroup uniformly for all virtually nilpotent groups. We also provide evidence towards the existence of a group GG with a subgroup H<GH<G of index 2, such that the submonoid membership problem is decidable in HH but not in GG.

Keywords

Cite

@article{arxiv.2405.12921,
  title  = {Is decidability of the Submonoid Membership Problem closed under finite extensions?},
  author = {Doron Shafrir},
  journal= {arXiv preprint arXiv:2405.12921},
  year   = {2024}
}