English

Symmetry groups of hyperbolic links and their complements

Geometric Topology 2025-04-07 v2

Abstract

We explicitly construct a sequence of hyperbolic links {L4n}\{ L_{4n} \} where the number of symmetries of each S3L4n\mathbb{S}^{3} \setminus L_{4n} that are not induced by symmetries of the pair (S3,L4n)(\mathbb{S}^{3}, L_{4n}) grows linearly with n. Specifically, [Sym(S3L4n):Sym(S3,L4n)]=8n[Sym(\mathbb{S}^{3} \setminus L_{4n}) : Sym(\mathbb{S}^{3}, L_{4n})] =8n \rightarrow \infty as nn \rightarrow \infty. For this construction, we start with a family of minimally twisted chain links, {C4n}\{ C_{4n} \}, where Sym(S3,C4n)Sym(\mathbb{S}^{3}, C_{4n}) and Sym(S3C4n)Sym(\mathbb{S}^{3} \setminus C_{4n}) coincide and grow linearly with nn. We then perform a particular type of homeomorphism on S3C4n\mathbb{S}^{3} \setminus C_{4n} to produce another link complement S3L4n\mathbb{S}^{3} \setminus L_{4n} where we can uniformly bound Sym(S3,L4n)|Sym(\mathbb{S}^{3}, L_{4n})| using a combinatorial condition based on linking number. A more general result highlighting how to control symmetry groups of hyperbolic links is provided, which has potential for further application.

Keywords

Cite

@article{arxiv.2403.17616,
  title  = {Symmetry groups of hyperbolic links and their complements},
  author = {Christian Millichap and Rolland Trapp},
  journal= {arXiv preprint arXiv:2403.17616},
  year   = {2025}
}

Comments

15 pages, 3 figures, accepted for publication in The Journal of Knot Theory and Its Ramifications