{ "id": "1312.0407", "version": "v1", "published": "2013-12-02T10:48:47.000Z", "updated": "2013-12-02T10:48:47.000Z", "title": "Independence and Matching Number in Graphs with Maximum Degree 4", "authors": [ "Felix Joos" ], "comment": "9 pages", "journal": "Discrete Math. 323 (2014) 1-6", "categories": [ "math.CO" ], "abstract": "We prove that $\\frac{7}{4}\\alpha(G)+\\beta(G)\\geq n(G)$ and $\\alpha(G)+\\frac{3}{2}\\beta(G)\\geq n(G)$ for every triangle-free graph $G$ with maximum degree at most $4$, where $\\alpha(G)$ is the independence number and $\\beta(G)$ is the matching number of $G$, respectively. These results are sharp for a graph on $13$ vertices. Furthermore we show $\\chi(G)\\leq \\frac{7}{4}\\omega(G)$ for $\\{3K_1,K_1\\cup K_5\\}$-free graphs, where $\\chi(G)$ is the chromatic number and $\\omega(G)$ is the clique number of $G$, respectively.", "revisions": [ { "version": "v1", "updated": "2013-12-02T10:48:47.000Z" } ], "analyses": { "keywords": [ "maximum degree", "matching number", "triangle-free graph", "clique number" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1312.0407J" } } }