IJPAM: Volume 36, No. 3 (2007)



Facultad de Ciencias
Universidad de Los Andes
Mérida, 5101, VENEZUELA


Abstract.The energy of a graph is defined as
, where
are the eigenvalues of the adjacency matrix of
. Recently, many authors have considered the problem of generating pairs of
non-cospectral equienergetic graphs. Since every graph
can be identified
with a symmetric digraph
, and the concept of the energy was
recently generalized to digraphs, it is natural to consider the problem of
generating pairs of non-symmetric, non-cospectral and equienergetic digraphs.
Received: January 10, 2007
AMS Subject Classification: 05C25
Key Words and Phrases: energy of a graph, eigenvalues of the adjacency matrix, non-cospectral equienergetic graphs, symmetric digraph, non-symmetric digraphs, non-cospectral digraphs, equienergetic digraphs
Source: International Journal of Pure and Applied Mathematics
ISSN: 1311-8080
Year: 2007
Volume: 36
Issue: 3