EQUIENERGETIC AND ALMOST-EQUIENERGETIC TREES

作者：Miljkovic Olga^*; Furtula Boris; Radenkovic Slavko; Gutman Ivan

来源：MATCH-Communications in Mathematical and in Computer Chemistry, 2009, 61(2): 451-461.

The energy E(G) of a graph G is equal to the sum of the absolute values of the eigenvalues of G. Two graphs G(a) and G(b) are said to be equienergetic if E(G(a)) = E(G(b)). Numerous families of non-cospectral eqnienergetic graphs have been reported so far. However, until now it was not noticed that there exist pairs of graphs whose energies differ insignificantly. We refer to such graphs as almost-equienergetic. A detailed study of almost-equienergetic trees is provided.

• 出版日期2009