{ "id": "2002.09709", "version": "v1", "published": "2020-02-22T14:32:05.000Z", "updated": "2020-02-22T14:32:05.000Z", "title": "Knot diagrams on a punctured sphere as a model of string figures", "authors": [ "Masafumi Arai", "Kouki Taniyama" ], "comment": "7 pages, 6 figures", "categories": [ "math.GT" ], "abstract": "A string figure is topologically a trivial knot lying on an imaginary plane orthogonal to the fingers with some crossings. The fingers prevent cancellation of these crossings. As a mathematical model of string figure we consider a knot diagram on the $xy$-plane in $xyz$-space missing some straight lines parallel to the $z$-axis. These straight lines correspond to fingers. We study minimal number of crossings of these knot diagrams under Reidemeister moves missing these lines.", "revisions": [ { "version": "v1", "updated": "2020-02-22T14:32:05.000Z" } ], "analyses": { "subjects": [ "57M25" ], "keywords": [ "knot diagram", "string figure", "punctured sphere", "fingers prevent cancellation", "imaginary plane orthogonal" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }