{ "id": "1302.4209", "version": "v1", "published": "2013-02-18T10:17:29.000Z", "updated": "2013-02-18T10:17:29.000Z", "title": "On The b-Chromatic Number of Regular Bounded Graphs", "authors": [ "Amine El Sahili", "Mekkia Kouider", "Maidoun Mortada" ], "categories": [ "math.CO" ], "abstract": "A $b$-coloring of a graph is a proper coloring such that every color class contains a vertex adjacent to at least one vertex in each of the other color classes. The $b$-chromatic number of a graph $G$, denoted by $b(G)$, is the maximum integer $k$ such that $G$ admits a $b$-coloring with $k$ colors. El Sahili and Kouider conjectured that $b(G)=d+1$ for $d$-regular graph with girth 5, $d\\geq4$. In this paper, we prove that this conjecture holds for $d$-regular graph with at least $d^3+d$ vertices. More precisely we show that $b(G)=d+$1 for $d$-regular graph with at least $d^3+d$ vertices and containing no cycle of order 4. We also prove that $b(G)=d+1$ for $d$-regular graphs with at least $2d^3+2d-2d^2$ vertices improving Cabello and Jakovac bound.", "revisions": [ { "version": "v1", "updated": "2013-02-18T10:17:29.000Z" } ], "analyses": { "keywords": [ "regular bounded graphs", "regular graph", "b-chromatic number", "color class contains", "vertex adjacent" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1302.4209E" } } }