{ "id": "1201.2983", "version": "v1", "published": "2012-01-14T03:39:01.000Z", "updated": "2012-01-14T03:39:01.000Z", "title": "Graphs with large generalized 3-connectivity", "authors": [ "Hengzhe Li", "Xueliang Li", "Yaping Mao", "Yuefang Sun" ], "comment": "9 pages", "categories": [ "math.CO" ], "abstract": "Let $S$ be a nonempty set of vertices of a connected graph $G$. A collection $T_1,..., T_\\ell$ of trees in $G$ is said to be internally disjoint trees connecting $S$ if $E(T_i)\\cap E(T_j)= \\emptyset$ and $V(T_i)\\cap V(T_j)=S$ for any pair of distinct integers $i, j$, where $1 \\leq i, j \\leq r$. For an integer $k$ with $2 \\leq k \\leq n$, the generalized $k$-connectivity $\\kappa_k(G)$ of $G$ is the greatest positive integer $r$ such that $G$ contains at least $r$ internally disjoint trees connecting $S$ for any set $S$ of $k$ vertices of $G$. Obviously, $\\kappa_2(G)$ is the connectivity of $G$. In this paper, sharp upper and lower bounds of $\\kappa_3(G)$ are given for a connected graph $G$ of order $n$, that is, $1 \\leq \\kappa_3(G) \\leq n - 2$. Graphs of order $n$ such that $\\kappa_3(G) = n - 2, n - 3$ are characterized, respectively.", "revisions": [ { "version": "v1", "updated": "2012-01-14T03:39:01.000Z" } ], "analyses": { "subjects": [ "05C40", "05C05" ], "keywords": [ "internally disjoint trees connecting", "connected graph", "lower bounds", "sharp upper" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1201.2983L" } } }