Coefficients of Randic and Sombor characteristic polynomials of some graph types

Let GG be a graph. The energy of GG is defined as the summation of absolute values of the eigenvalues of the adjacency matrix of GG. It is possible to study several types of graph energy originating from defining various adjacency matrices defined by correspondingly different types of graph invariants. The first step is computing the characteristic polynomial of the defined adjacency matrix of GG for obtaining the corresponding energy of GG. In this paper, formulae for the coefficients of the characteristic polynomials of both the Randic and the Sombor adjacency matrices of path graph PnPn , cycle graph CnCn are presented. Moreover, we obtain the five coefficients of the characteristic polynomials of both Randic and Sombor adjacency matrices of a special type of 3−regular graph RnRn.

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  • Bapat, R. B., Graphs and Matrices, Springer, London, 2010. http://dx.doi.org/10.1007/978-1-84882-981-7
  • Bozkurt, S. B., Güngör, A. D., Gutman, I., Çevik, A. S., Randic matrix and Randic energy, MATCH Commun. Math. Comput. Chem., 64(1) (2010), 239–250.
  • Cvetkovic, D. M., Doob, M., Sachs, H., Spectra of Graphs – Theory and Application, Academic Press, New York, 1980.
  • Das, K. C., Sorgun, S., Xu, K., On the Randic energy of graphs, MATCH Commun. Math. Comput. Chem., 72(1) (2014), 227–238.
  • Ghanbari, N., On the Sombor characteristic polynomial and Sombor energy of a graph, arXiv: 2108.08552, 2021. https://doi.org/10.48550/arXiv.2108.08552
  • Gutman, I., The energy of a graph, Ber. Math-Statist. Sekt. Forschungsz. Graz, 103 (1978), 1–22.
  • Gutman, I., Impact of the Sachs theorem on theoretical chemistry: A participant’s testimony, MATCH Commun. Math. Comput. Chem., 48 (2003), 17–34.
  • Gutman, I., Furtula, B., Bozkurt, S. B., On Randic energy, Linear Algebra Appl., 442 (2014), 50–57. http://dx.doi.org/10.1016/j.laa.2013.06.010
  • Gutman, I., Geometric approach to degree-based topological indices: Sombor indices, MATCH Commun. Math. Comput. Chem., 86(1) (2021), 11–16.
  • Gutman, I., Spectrum and energy of the Sombor matrix, Vojno tehn. glas., 69(3) (2021), 551–561. http://dx.doi.org/10.5937/vojtehg69-31995
  • Gutman, I., Redzepovic, I., Rada, J., Relating energy and Sombor energy, Contrib. Math., 4 (2021), 41–44. DOI: 10.47443/cm.2021.0054
  • Gutman, I., Redzepovic, I., Sombor energy and Huckel rule, Discrete Math. Lett., 9 (2022), 67–71. DOI: 10.47443/dml.2021.s211
  • Janezic, D., Milicevic, A., Nikolic, S., Trinajstic, N., Graph Theoretical Matrices in Chemistry, CRC Press, Boca Raton, 2015. http://dx.doi.org/10.1201/b18389
  • Jayanna, G. K., Gutman, I., On characteristic polynomial and energy of Sombor matrix, Open J. Discret. Appl. Math., 4 (2021), 29–35. http://dx.doi.org/10.30538/psrp-odam2021.0062
  • Li, X., Shi, Y., Gutman, I., Graph Energy, Springer, New York, 2012. http://dx.doi.org/10.1007/978-1-4614-4220-2
  • Randic, M., On characterization of molecular branching, J. Am. Chem. Soc., 97(23) (1975), 6609–6615. http://dx.doi.org/10.1021/ja00856a001
  • Redzepovic, I., Gutman, I., Comparing energy and Sombor energy–An empirical study, MATCH Commun. Math. Comput. Chem., 88(1) (2022), 133–140.
  • Sachs, H., Uber selbstkomplement¨are graphen, Publ. Math. Debrecen, 9 (1962), 270-288.