{ "id": "1302.2599", "version": "v1", "published": "2013-02-11T20:15:58.000Z", "updated": "2013-02-11T20:15:58.000Z", "title": "$(3,1)^*$-choosability of planar graphs without adjacent short cycles", "authors": [ "Min Chen", "Andre Raspaud" ], "categories": [ "math.CO" ], "abstract": "A list assignment of a graph $G$ is a function $L$ that assigns a list $L(v)$ of colors to each vertex $v\\in V(G)$. An $(L,d)^*$-coloring is a mapping $\\pi$ that assigns a color $\\pi(v)\\in L(v)$ to each vertex $v\\in V(G)$ so that at most $d$ neighbors of $v$ receive color $\\pi(v)$. A graph $G$ is said to be $(k,d)^*$-choosable if it admits an $(L,d)^*$-coloring for every list assignment $L$ with $|L(v)|\\ge k$ for all $v\\in V(G)$. In 2001, Lih et al. \\cite{LSWZ-01} proved that planar graphs without 4- and $l$-cycles are $(3,1)^*$-choosable, where $l\\in \\{5,6,7\\}$. Later, Dong and Xu \\cite{DX-09} proved that planar graphs without 4- and l-cycles are $(3,1)^*$-choosable, where $l\\in \\{8,9\\}$. There exist planar graphs containing 4-cycles that are not $(3,1)^*$-choosable (Crown, Crown and Woodall, 1986 \\cite{CCW-86}). This partly explains the fact that in all above known sufficient conditions for the $(3,1)^*$-choosability of planar graphs the 4-cycles are completely forbidden. In this paper we allow 4-cycles nonadjacent to relatively short cycles. More precisely, we prove that every planar graph without 4-cycles adjacent to 3- and 4-cycles is $(3,1)^*$-choosable. This is a common strengthening of all above mentioned results. Moreover as a consequence we give a partial answer to a question of Xu and Zhang \\cite{XZ-07} and show that every planar graph without 4-cycles is $(3,1)^*$-choosable.", "revisions": [ { "version": "v1", "updated": "2013-02-11T20:15:58.000Z" } ], "analyses": { "subjects": [ "05C15" ], "keywords": [ "planar graph", "adjacent short cycles", "choosability", "list assignment", "sufficient conditions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1302.2599C" } } }