English

On eigenvalues of double branched covers

Geometric Topology 2019-10-07 v1

Abstract

For a given knot, we study the minimal number of positive eigenvalues of the double branched cover over spanning surfaces for the knot. The value gives a lower bound for various genera, the dealternating number and the alternation number of knots, and we prove that Batson's bound for the non-orientable 4-genus gives an estimate of the value. In addition, we use the value to give a necessary condition for being quasi-alternating.

Keywords

Cite

@article{arxiv.1709.05617,
  title  = {On eigenvalues of double branched covers},
  author = {Kouki Sato},
  journal= {arXiv preprint arXiv:1709.05617},
  year   = {2019}
}

Comments

13 pages, 15 figures

R2 v1 2026-06-22T21:45:41.595Z