English

A characterisation of alternating knot exteriors

Geometric Topology 2017-06-14 v1

Abstract

We give a topological characterisation of alternating knot exteriors based on the presence of special spanning surfaces. This shows that alternating is a topological property of the knot exterior and not just a property of diagrams, answering an old question of Fox. We also give a characterisation of alternating link exteriors which have marked meridians. We then describe a normal surface algorithm which can decide if a knot is prime and alternating given a triangulation of its exterior as input.

Keywords

Cite

@article{arxiv.1511.04945,
  title  = {A characterisation of alternating knot exteriors},
  author = {Joshua Howie},
  journal= {arXiv preprint arXiv:1511.04945},
  year   = {2017}
}

Comments

23 pages, 7 figures