{ "id": "2007.07280", "version": "v1", "published": "2020-07-14T18:17:20.000Z", "updated": "2020-07-14T18:17:20.000Z", "title": "Cubic graphs induced by bridge trisections", "authors": [ "Jeffrey Meier", "Abigail Thompson", "Alexander Zupan" ], "comment": "18 pages, 17 color figures", "categories": [ "math.GT", "math.CO" ], "abstract": "Every embedded surface $\\mathcal{K}$ in the 4-sphere admits a bridge trisection, a decomposition of $(S^4,\\mathcal{K})$ into three simple pieces. In this case, the surface $\\mathcal{K}$ is determined by an embedded 1-complex, called the $\\textit{1-skeleton}$ of the bridge trisection. As an abstract graph, the 1-skeleton is a cubic graph $\\Gamma$ that inherits a natural Tait coloring, a 3-coloring of the edge set of $\\Gamma$ such that each vertex is incident to edges of all three colors. In this paper, we reverse this association: We prove that every Tait-colored cubic graph is isomorphic to the 1-skeleton of a bridge trisection corresponding to an unknotted surface. When the surface is nonorientable, we show that such an embedding exists for every possible normal Euler number. As a corollary, every tri-plane diagram for a knotted surface can be converted to a tri-plane diagram for an unknotted surface via crossing changes and interior Reidemeister moves.", "revisions": [ { "version": "v1", "updated": "2020-07-14T18:17:20.000Z" } ], "analyses": { "subjects": [ "57Q45", "57M50", "05C15" ], "keywords": [ "bridge trisection", "tri-plane diagram", "normal euler number", "unknotted surface", "interior reidemeister moves" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable" } } }