{ "id": "2304.06276", "version": "v1", "published": "2023-04-13T05:26:04.000Z", "updated": "2023-04-13T05:26:04.000Z", "title": "Distinguishing 2-knots admitting circle actions by fundamental groups", "authors": [ "Mizuki Fukuda", "Masaharu Ishikawa" ], "comment": "9 pages", "categories": [ "math.GT" ], "abstract": "A 2-sphere embedded in the 4-sphere invariant under a circle action is called a branched twist spin. A branched twist spin is constructed from a 1-knot in the 3-sphere and a pair of coprime integers uniquely. In this paper, we study, for each pair of coprime integers, if two different 1-knots yield the same branched twist spin, and prove that such a pair of 1-knots does not exist in most cases. Fundamental groups of 3-orbiolds of cyclic type are obtained as quotient groups of the fundamental groups of the complements of branched twist spins. We use these groups for distinguishing branched twist spins.", "revisions": [ { "version": "v1", "updated": "2023-04-13T05:26:04.000Z" } ], "analyses": { "subjects": [ "57Q45", "57M05", "57M10", "57M27" ], "keywords": [ "fundamental groups", "admitting circle actions", "coprime integers", "distinguishing branched twist spins", "quotient groups" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable" } } }