文摘
The maximum local connectivity was first introduced by Bollobás. The problem of determining the maximum number of edges in a graph with \(\overline{\kappa }\le \ell \) has been studied extensively. We consider a generalization of the above concept and problem. For \(S\subseteq V(G)\) and \(|S|\ge 2\), the generalized local connectivity \(\kappa (S)\) is the maximum number of internally disjoint trees connecting \(S\) in \(G\). The parameter \(\overline{\kappa }_k(G)=\max \{\kappa (S)\,|\,S\subseteq V(G),|S|=k\}\) is called the maximum generalized local connectivity of \(G\). In this paper the problem of determining the largest number \(f(n;\overline{\kappa }_k\le \ell )\) of edges for graphs of order \(n\) that have maximum generalized local connectivity at most \(\ell \) is considered. The exact value of \(f(n;\overline{\kappa }_k\le \ell )\) for \(k=n,n-1\) is determined. For a general \(k\), we construct a graph to obtain a sharp lower bound. Keywords (Edge-)connectivity Steiner tree Internally (edge-)disjoint trees Packing generalized local (edge-)connectivity