Estimating vertex-degree-based energies

Keywords: vertex-degree-based graph invariant, vertex-degree-based matrix, vertex-degree-based energy, energy (of graph)

Abstract


Introduction/purpose: In the current literature, several dozens of vertexdegree-based (VDB) graph invariants are being studied. To each such invariant, a matrix can be associated. The VDB energy is the energy (= sum of the absolute values of the eigenvalues) of the respective VDB matrix. The paper examines some general properties of the VDB energy of bipartite graphs.

Results: Estimates (lower and upper bounds) are established for the VDB energy of bipartite graphs in which there are no cycles of size divisible by 4, in terms of ordinary graph energy.

Conclusion: The results of the paper contribute to the spectral theory of VDB matrices, especially to the general theory of VDB energy.

Author Biography

Ivan Gutman, University of Kragujevac, Faculty of Science, Kragujevac, Republic of Serbia

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Published
2022/01/05
Section
Original Scientific Papers