{ "id": "1302.2158", "version": "v3", "published": "2013-02-08T21:25:22.000Z", "updated": "2016-01-06T15:13:42.000Z", "title": "Three-coloring triangle-free graphs on surfaces II. 4-critical graphs in a disk", "authors": [ "Zdenek Dvorak", "Daniel Kral", "Robin Thomas" ], "comment": "45 pages, 2 figures This version: Minor fix to the statement of one lemma, bibliography update", "categories": [ "math.CO", "cs.DM" ], "abstract": "Let G be a plane graph of girth at least five. We show that if there exists a 3-coloring phi of a cycle C of G that does not extend to a 3-coloring of G, then G has a subgraph H on O(|C|) vertices that also has no 3-coloring extending phi. This is asymptotically best possible and improves a previous bound of Thomassen. In the next paper of the series we will use this result and the attendant theory to prove a generalization to graphs on surfaces with several precolored cycles.", "revisions": [ { "version": "v2", "updated": "2013-05-25T15:28:37.000Z", "comment": "45 pages, 2 figures", "journal": null, "doi": null }, { "version": "v3", "updated": "2016-01-06T15:13:42.000Z" } ], "analyses": { "subjects": [ "05C15", "05C10", "G.2.2" ], "keywords": [ "three-coloring triangle-free graphs", "plane graph", "attendant theory", "precolored cycles", "extending phi" ], "note": { "typesetting": "TeX", "pages": 45, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1302.2158D" } } }