English

Independence of volume and genus $g$ bridge numbers

Geometric Topology 2016-03-30 v2

Abstract

A theorem of Jorgensen and Thurston implies that the volume of a hyperbolic 3-manifold is bounded below by a linear function of its Heegaard genus. Heegaard surfaces and bridge surfaces often exhibit similar topological behavior; thus it is natural to extend this comparison to ask whether a (g,b)(g,b)-bridge surface for a knot KK in S3S^3 carries any geometric information related to the knot exterior. In this paper, we show that (unlike in the case of Heegaard splittings) hyperbolic volume and genus gg bridge numbers are completely independent. That is, for any gg, we construct explicit sequences of knots with bounded volume and unbounded genus gg bridge number, and explicit sequences of knots with bounded genus gg bridge number and unbounded volume.

Keywords

Cite

@article{arxiv.1512.03869,
  title  = {Independence of volume and genus $g$ bridge numbers},
  author = {Jessica S. Purcell and Alexander Zupan},
  journal= {arXiv preprint arXiv:1512.03869},
  year   = {2016}
}

Comments

14 pages, 5 figures