Author/Authors :
Nandeesh، K. Channegowda نويسنده Department of Mathematics,Karnatak University,Dharwad,India , , Gutman، Ivan نويسنده Faculty of Science,University of Kragujevac,Kragujevac,Serbia , , Li، Xueliang نويسنده Center for Combinatorics and LPMC-TJKLC,Nankai University,Tianjin,China , , Ramane، Harishchandra S. نويسنده Department of Mathematics,Karnatak University,Dharwad,India ,
Abstract :
Let D be a digraph with skewadjacency matrix S(D). The skew energy of D is defined as the sum of the norms of all eigenvalues of S(D). Two digraphs are said to be skew equienergetic if their skew energies are equal. We establish an expression for the characteristic polynomial of the skew adjacency matrix of the join of two digraphs, and for the respective skew energy, and thereby construct noncospectral, skew equienergetic digraphs on n vertices, for all n ≥ 6. Thus we arrive at the solution of some open problems proposed in [X. Li, H. Lian, A survey on the skew energy of oriented graphs, arXiv:1304.5707].
