Extremal Energy of Digraphs with Two Linear Subdigraphs

Rashid Farooq, Mehtab Khan, Yasir Masood

The eigenvalues of a digraph are the eigenvalues of its adjacency matrix. The sum of the absolute values of the real part of the eigenvalues is called the energy of the digraph. The extremal energy of bicyclic digraphs with vertex-disjoint directed cycles is known. In this paper, we consider a class of bicyclic digraphs with exactly two linear subdigraphs of equal length. We find the minimal and maximal energy among the digraphs in this class.