{ "id": "1208.4995", "version": "v1", "published": "2012-08-24T15:01:39.000Z", "updated": "2012-08-24T15:01:39.000Z", "title": "A characterization of the edge connectivity of direct products of graphs", "authors": [ "Simon Spacapan" ], "categories": [ "math.CO" ], "abstract": "The direct product of graphs $G=(V(G),E(G))$ and $H=(V(H),E(H))$ is the graph, denoted as $G\\times H$, with vertex set $V(G\\times H)=V(G)\\times V(H)$, where vertices $(x_1,y_1)$ and $(x_2,y_2)$ are adjacent in $G\\times H$ if $x_1x_2\\in E(G)$ and $y_1y_2\\in E(H)$. The edge connectivity of a graph $G$, denoted as $\\lambda(G)$, is the size of a minimum edge-cut in $G$. We introduce a function $\\psi$ and prove the following formula %for the edge-connectivity of direct products $$\\lambda (G\\times H)=\\min {2\\lambda(G)|E(H)|,2\\lambda(H)|E(G)|,\\delta(G\\times H), \\psi(G,H), \\psi(H,G)} .$$ We also describe the structure of every minimum edge-cut in $G\\times H$.", "revisions": [ { "version": "v1", "updated": "2012-08-24T15:01:39.000Z" } ], "analyses": { "keywords": [ "direct product", "edge connectivity", "minimum edge-cut", "characterization" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1208.4995S" } } }