On degeneracy of 𝒜-eigenvalue–based molecular descriptors and 𝑟-equienergetic chemical trees

Abstract

Among more than two hundreds of eigenvalue-based topological indices only a couple of them are defined using the eigenvalues devised from the adjacency matrix of a graph. The resolvent energy is probably the most recent-one such an index. In this article, the degeneracy of the energy, Estrada index, and the resolvent energy is presented. The specious degeneracy of the resolvent energy in the case of chemical trees is discussed. Then, the data on searching for resolvent equienergetic chemical trees is given