{ "id": "1007.1615", "version": "v1", "published": "2010-07-09T15:49:18.000Z", "updated": "2010-07-09T15:49:18.000Z", "title": "Linear Choosability of Sparse Graphs", "authors": [ "Daniel W. Cranston", "Gexin Yu" ], "comment": "12 pages, 2 figures", "journal": "Discrete Math. Vol. 311, no. 17, 2011, pp. 1910-1917", "categories": [ "math.CO" ], "abstract": "We study the linear list chromatic number, denoted $\\lcl(G)$, of sparse graphs. The maximum average degree of a graph $G$, denoted $\\mad(G)$, is the maximum of the average degrees of all subgraphs of $G$. It is clear that any graph $G$ with maximum degree $\\Delta(G)$ satisfies $\\lcl(G)\\ge \\ceil{\\Delta(G)/2}+1$. In this paper, we prove the following results: (1) if $\\mad(G)<12/5$ and $\\Delta(G)\\ge 3$, then $\\lcl(G)=\\ceil{\\Delta(G)/2}+1$, and we give an infinite family of examples to show that this result is best possible; (2) if $\\mad(G)<3$ and $\\Delta(G)\\ge 9$, then $\\lcl(G)\\le\\ceil{\\Delta(G)/2}+2$, and we give an infinite family of examples to show that the bound on $\\mad(G)$ cannot be increased in general; (3) if $G$ is planar and has girth at least 5, then $\\lcl(G)\\le\\ceil{\\Delta(G)/2}+4$.", "revisions": [ { "version": "v1", "updated": "2010-07-09T15:49:18.000Z" } ], "analyses": { "subjects": [ "05C15" ], "keywords": [ "sparse graphs", "linear choosability", "linear list chromatic number", "maximum average degree", "infinite family" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1007.1615C" } } }