English

Every knot has characterising slopes

Geometric Topology 2018-08-08 v2

Abstract

Let K be a knot in the 3-sphere. A slope p/q is said to be characterising for K if whenever p/q surgery on K is homeomorphic, via an orientation-preserving homeomorphism, to p/q surgery on another knot K' in the 3-sphere, then K and K' are isotopic. It was an old conjecture of Gordon, proved by Kronheimer, Mrowka, Ozsvath and Szabo, that every slope is characterising for the unknot. In this paper, we show that every knot K has infinitely many characterising slopes, confirming a conjecture of Baker and Motegi. In fact, p/q is characterising for K provided |p| is at most |q| and |q| is sufficiently large.

Keywords

Cite

@article{arxiv.1707.00457,
  title  = {Every knot has characterising slopes},
  author = {Marc Lackenby},
  journal= {arXiv preprint arXiv:1707.00457},
  year   = {2018}
}

Comments

15 pages, no figures; final version

R2 v1 2026-06-22T20:36:01.908Z