Fang Duan

collaborators

2 papers

math.CO2018

A complete characterization of graphs with exactly two positive eigenvalues

Fang Duan, Qiongxiang Huang, Xueyi Huang +2

In 1977 Smith characterized graphs with exactly one positive eigenvalue. Since then, many particular results related to graphs with exactly two positive eigenvalues have emerged. I…

math.CO2018

On graphs with exactly two positive eigenvalues

Fang Duan, Qiongxiang Huang, Xueyi Huang

The inertia of a graph $G$ is defined to be the triplet $I n (G) = (p (G), n (G),$ $η (G))$ , where $p (G)$ , $n (G)$ and $η (G)$ are the numbers of positive, negative and zero eigenvalues…