{ "id": "1304.0083", "version": "v1", "published": "2013-03-30T10:13:00.000Z", "updated": "2013-03-30T10:13:00.000Z", "title": "Characterizations of 2-Colorable (Bipartite) and 3-Colorable Graphs", "authors": [ "E. Sampathkumar", "M. A. Sriraj" ], "categories": [ "math.CO" ], "abstract": "A \\emph{directional labeling} of an edge $\\emph{uv}$ in a graph $G=(V,E)$ by an ordered pair $ab$ is a labeling of the edge $uv$ such that the label on $uv$ in the direction from $u$ to $v$ is $\\ell(uv)=ab$, and $\\ell(vu)=ba$. New characterizations of 2-colorable (bipartite) and 3-colorable graphs are obtained in terms of directional labeling of edges of a graph by ordered pairs $ab$ and $ba$. In addition we obtain characterizations of 2-colorable and 3-colorable graphs in terms of matrices called directional adjacency matrices.", "revisions": [ { "version": "v1", "updated": "2013-03-30T10:13:00.000Z" } ], "analyses": { "keywords": [ "characterizations", "ordered pair", "directional adjacency matrices" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1304.0083S" } } }