English

L-space knots with tunnel number >1 by experiment

Geometric Topology 2026-02-10 v2

Abstract

In Dunfield's catalog of the hyperbolic manifolds in the SnapPy census which are complements of L-space knots in S3S^3, we determine that 2222 have tunnel number 22 while the remaining all have tunnel number 11. Notably, these 2222 manifolds contain 99 asymmetric L-space knot complements. Furthermore, using SnapPy and KLO we find presentations of these 2222 knots as closures of positive braids that realize the Morton-Franks-Williams bound on braid index. The smallest of these has genus 1212 and braid index 44.

Keywords

Cite

@article{arxiv.1909.00790,
  title  = {L-space knots with tunnel number >1 by experiment},
  author = {Chris Anderson and Kenneth L. Baker and Xinghua Gao and Marc Kegel and Khanh Le and Kyle Miller and Sinem Onaran and Geoffrey Sangston and Samuel Tripp and Adam Wood and Ana Wright},
  journal= {arXiv preprint arXiv:1909.00790},
  year   = {2026}
}

Comments

This is a significant expansion/rewrite of the original version. The title and abstract have both changed to reflect this. Relevant code is included in the body of the article itself. Originally, this was a note that collected the results of an "office hour" session on the use of SnapPy and KLO held at the ICERM workshop Perspectives on Dehn Surgery, July 15--19, 2019