{ "id": "2102.00888", "version": "v1", "published": "2021-02-01T15:01:09.000Z", "updated": "2021-02-01T15:01:09.000Z", "title": "On values of $\\mathfrak{sl}_3$ weight system on chord diagrams whose intersection graph is complete bipartite", "authors": [ "Zhuoke Yang" ], "categories": [ "math.CO", "math.GT" ], "abstract": "Each knot invariant can be extended to singular knots according to the skein rule. A Vassiliev invariant of order at most $n$ is defined as a knot invariant that vanishes identically on knots with more than $n$ double points. A chord diagram encodes the order of double points along a singular knot. A Vassiliev invariant of order $n$ gives rise to a function on chord diagrams with $n$ chords. Such a function should satisfy some conditions in order to come from a Vassiliev invariant. A weight system is a function on chord diagrams that satisfies so-called 4-term relations. Given a Lie algebra $\\mathfrak{g}$ equipped with a non-degenerate invariant bilinear form, one can construct a weight system with values in the center of the universal enveloping algebra $U(\\mathfrak{g})$. In this paper, we calculate $\\mathfrak{sl}_3$ weight system for chord diagram whose intersection graph is complete bipartite graph $K_{2,n}$.", "revisions": [ { "version": "v1", "updated": "2021-02-01T15:01:09.000Z" } ], "analyses": { "keywords": [ "chord diagram", "weight system", "complete bipartite", "intersection graph", "vassiliev invariant" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }