On the skew energy of oriented unicyclic digraphs

摘要

The concept of the skew energy of a digraph was introduced by Adiga, Balakrishnan and So in 2010. Let G be an oriented graph of order n and λ_1, λ_2,..., λ_n denote all the eigenvalues of the skew-adjacency matrix of G. The skew energy ε_s(G) = ∑_(i=1)~n|λ_i|. Hou, Shen and Zhang determined the minimal and the second minimal skew energy of the oriented unicyclic graphs. In this paper, the oriented unicyclic graphs with the third, fourth and fifth minimal skew energy are characterized, respectively.