کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4603280 1631166 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
On eigensharp and almost eigensharp graphs
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات اعداد جبر و تئوری
پیش نمایش صفحه اول مقاله
On eigensharp and almost eigensharp graphs
چکیده انگلیسی

The minimum number of complete bipartite subgraphs needed to partition the edges of a graph G is denoted by b(G). A known lower bound on b(G) states that b(G)⩾ max{p(G),q(G)}, where p(G) and q(G) are the numbers of positive and negative eigenvalues of the adjacency matrix of G, respectively. When equality is attained, G is said to be eigensharp and when b(G)=max{p(G),q(G)}+1, G is called an almost eigensharp graph. In this paper, we investigate the eigensharpness of graphs with at most one cycle and products of some families of graphs. Among the other results, we show that Pm∨Pn, Cm∨Pn for and Qn when n is odd are eigensharp. We obtain some results on almost eigensharp graphs as well.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Linear Algebra and its Applications - Volume 429, Issues 11–12, 1 December 2008, Pages 2746-2753