English

Embedding $\mathbb{Q}$ into a Finitely Presented Group

Group Theory 2022-03-29 v4

Abstract

We observe that the group of all lifts of elements of Thompson's group TT to the real line is finitely presented and contains the additive group Q\mathbb{Q} of the rational numbers. This gives an explicit realization of the Higman embedding theorem for Q\mathbb{Q}, answering a Kourovka notebook question of Martin Bridson and Pierre de la Harpe.

Keywords

Cite

@article{arxiv.2005.02036,
  title  = {Embedding $\mathbb{Q}$ into a Finitely Presented Group},
  author = {James Belk and James Hyde and Francesco Matucci},
  journal= {arXiv preprint arXiv:2005.02036},
  year   = {2022}
}

Comments

7 pages, no figures; to appear in $\textit{Bulletin of the American Mathematical Society}$. This version contains only the embedding of $\mathbb{Q}$ into the group of all lifts of elements of Thompson's group $T$ to the real line. The discussion of the group $T\mathcal{A}$ will appear elsewhere

R2 v1 2026-06-23T15:19:00.092Z