English

Presentations for Singly-Cusped Bianchi Groups

Group Theory 2025-08-15 v1 Geometric Topology

Abstract

We produce a complete list of group presentations for singly-cusped Bianchi groups, PSL2(Od)PSL_2 (\mathcal{O}_d) where Od\mathcal{O}_d is the ring of integers for Q(d)\mathbb{Q}(\sqrt{d}) and dd is -1, -2, -3, -7, -11, -19, -43, -67, or -163. To do this, we apply a theorem due to Macbeath to a sufficiently large horoball, treating the Bianchi groups as discrete subgroups of isometries for H3\mathbf{H}^3. As far as we know, explicit presentations were not previously known when dd is -43, -67, or -163.

Cite

@article{arxiv.2206.01262,
  title  = {Presentations for Singly-Cusped Bianchi Groups},
  author = {Tanner Reese},
  journal= {arXiv preprint arXiv:2206.01262},
  year   = {2025}
}

Comments

submitted to Experimental Mathematics

R2 v1 2026-06-24T11:37:38.993Z