{ "id": "1009.2279", "version": "v1", "published": "2010-09-13T01:18:09.000Z", "updated": "2010-09-13T01:18:09.000Z", "title": "Genus two Heegaard splittings of exteriors of 1-genus 1-bridge knots II", "authors": [ "Hiroshi Goda", "Chuichiro Hayashi" ], "comment": "21 pages, 7 figures", "categories": [ "math.GT" ], "abstract": "A knot K is called a 1-genus 1-bridge knot in a 3-manifold M if (M,K) has a Heegaard splitting (V_1,t_1)\\cup (V_2,t_2) where V_i is a solid torus and t_i is a boundary parallel arc properly embedded in V_i. If the exterior of a knot has a genus 2 Heegaard splitting, we say that the knot has an unknotting tunnel. Naturally the exterior of a 1-genus 1-bridge knot K allows a genus 2 Heegaard splitting, i.e., K has an unknotting tunnel. But, in general, there are unknotting tunnels which are not derived form this procedure. Some of them may be levelled with the torus \\partial V_1=\\partial V_2, whose case was studied in our previous paper. In this paper, we consider the remaining case.", "revisions": [ { "version": "v1", "updated": "2010-09-13T01:18:09.000Z" } ], "analyses": { "subjects": [ "57M25" ], "keywords": [ "heegaard splitting", "unknotting tunnel", "boundary parallel arc", "solid torus" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1009.2279G" } } }