摘要
The sum of positive eigenvalues and the number of the edges of a graph G are denoted by S(G) and #E(G) respectively. C. Delorme[1] put forward the question: What is the lower bound of S(G) for a given #E(G)? Is it In this paper we give an affirmative answer to the question.
The sum of positive eigenvalues and the number of the edges of a graph G are denoted by S(G) and #E(G) respectively. C. Delorme[1] put forward the question: What is the lower bound of S(G) for a given #E(G)? Is it In this paper we give an affirmative answer to the question.
