Iota energy of weighted digraphs

The eigenvalues of a digraph are the eigenvalues of its adjacency matrix. The iota energy of a digraph is recently defined as the sum of absolute values of imaginary part of its eigenvalues. In this paper, we extend the concept of iota energy of digraphs to weighted digraphs. We compute the iota ene...

Full description

Bibliographic Details
Main Authors: Sumaira Hafeez, Mehtab Khan
Format: Article
Language:English
Published: University of Isfahan 2018-09-01
Series:Transactions on Combinatorics
Subjects:
Online Access:http://toc.ui.ac.ir/article_22707_8eb3ec61aa18a4a5a2445c45716a4a23.pdf
Description
Summary:The eigenvalues of a digraph are the eigenvalues of its adjacency matrix. The iota energy of a digraph is recently defined as the sum of absolute values of imaginary part of its eigenvalues. In this paper, we extend the concept of iota energy of digraphs to weighted digraphs. We compute the iota energy formulae for the positive and negative weight directed cycles. We also characterize the unicyclic weighted digraphs with cycle weight $ r in [-1, 1]backslash {0}$ having minimum and maximum iota energy. We obtain well known McClelland upper bound for the iota energy of weighted digraphs. Finally, we find the class of noncospectral equienergetic weighted digraphs.
ISSN:2251-8657
2251-8665