含有两个基本圈的简单图的N-G型代数连通度的界

摘要

Let G be a simple graph with a (G) and G, its algebraic connectivity and complement graph. It is proved that it holds for the algebraic connectivity of Nordhaus-Gaddum type for a graph G whose cycle rank is 2 that 1 ≤a(G)+a(G c ) by classification and con-crete reseach.%　　对任一个n阶简单图G，用a（G）表示G的代数连通度。在已有文献研究的基础上，通过分类研究和个别图具体研究，证明了对任一含有两个基本圈的简单图G，有1≤a（G）+a（G c ）。