Let $ A(G) $ and $ D(G) $ be the adjacency matrix and the degree diagonal matrix of a graph $ G $, respectively. For any real number $ \alpha \in[0, 1] $, Nikiforov recently defined the $ A_{\alpha} $-matrix of $ G $ as $ A_{\alpha}(G) = \alpha D(G)+(1-\alpha)A(G) $. The graph invariant $ S_{\alpha}^{p}(G) $ is the sum of the $ p $-th power of the $ A_{\alpha} $-eigenvalues of $ G $ for $ \frac{1}{2} < \alpha < 1 $, which has a close relation to the $ \alpha $-Estrada index. In this paper, we establish some bounds on $ S_{\alpha}^{p}(G) $ and characterize the extremal graphs. In particular, we present some bounds on $ S_{\alpha}^{p}(G) $ in terms of the degree sequences, order and size of $ G $ by using majorization techniques. Moreover, we give lower and upper bounds for $ S_{\alpha}^{p}(G) $ of a bipartite graph and characterize the extremal graphs.
Citation: Zhen Lin. On the sum of powers of the $ A_{\alpha} $-eigenvalues of graphs[J]. Mathematical Modelling and Control, 2022, 2(2): 55-64. doi: 10.3934/mmc.2022007
Let $ A(G) $ and $ D(G) $ be the adjacency matrix and the degree diagonal matrix of a graph $ G $, respectively. For any real number $ \alpha \in[0, 1] $, Nikiforov recently defined the $ A_{\alpha} $-matrix of $ G $ as $ A_{\alpha}(G) = \alpha D(G)+(1-\alpha)A(G) $. The graph invariant $ S_{\alpha}^{p}(G) $ is the sum of the $ p $-th power of the $ A_{\alpha} $-eigenvalues of $ G $ for $ \frac{1}{2} < \alpha < 1 $, which has a close relation to the $ \alpha $-Estrada index. In this paper, we establish some bounds on $ S_{\alpha}^{p}(G) $ and characterize the extremal graphs. In particular, we present some bounds on $ S_{\alpha}^{p}(G) $ in terms of the degree sequences, order and size of $ G $ by using majorization techniques. Moreover, we give lower and upper bounds for $ S_{\alpha}^{p}(G) $ of a bipartite graph and characterize the extremal graphs.
[1] | B. Zhou, On sum of powers of the Laplacian eigenvalues of graphs, Linear Algebra Appl., 429 (2008), 2239–2246. https://doi.org/10.1016/j.laa.2008.06.023 doi: 10.1016/j.laa.2008.06.023 |
[2] | J. Liu, B. Liu, A Laplacian-energy-like invariant of a graph, MATCH Commun. Math. Comput. Chem., 59 (2008), 355–372. |
[3] | G. H. Fath-Tabar, A. R. Ashrafi, I. Gutman, Note on Estrada and $L$-Estrada indices of graphs, Bull. Cl. Sci. Math. Nat. Sci. Math. No., 34 (2009), 1–16. |
[4] | I. Gutman, B. Mohar, The quasi-Wiener and the Kirchhoff indices coincide, J. Chem. Inf. Comput. Sci., 36 (1996), 982–985. https://doi.org/10.1021/ci960007t doi: 10.1021/ci960007t |
[5] | X. Chen, K. C. Das, Characterization of extremal graphs from Laplacian eigenvalues and the sum of powers of the Laplacian eigenvalues of graphs, Discrete Math., 338 (2015), 1252–1263. https://doi.org/10.1016/j.disc.2015.02.006 doi: 10.1016/j.disc.2015.02.006 |
[6] | K. C. Das, K. Xu, M. Liu, On sum of powers of the Laplacian eigenvalues of graphs, Linear Algebra Appl., 439 (2013), 3561–3575. https://doi.org/10.1016/j.laa.2013.09.036 doi: 10.1016/j.laa.2013.09.036 |
[7] | M. Liu, B. Liu, A note on sum of powers of the Laplacian eigenvalues of graphs, Appl. Math. Lett., 24 (2011), 249–252. https://doi.org/10.1016/j.aml.2010.09.013 doi: 10.1016/j.aml.2010.09.013 |
[8] | G. Tian, T. Huang, B. Zhou, A note on sum of powers of the Laplacian eigenvalues of bipartite graphs, Linear Algebra Appl., 430 (2009), 2503–2510. https://doi.org/10.1016/j.laa.2008.12.030 doi: 10.1016/j.laa.2008.12.030 |
[9] | B. Zhou, A. Ilić, On the sum of powers of Laplacian eigenvalues of bipartite graphs, Czechoslovak Math. J., 60 (2010), 1161–1169. https://doi.org/10.1007/s10587-010-0081-8 doi: 10.1007/s10587-010-0081-8 |
[10] | M. Liu, B. Liu, On sum of powers of the signless Laplacian eigenvalues of graphs, Hacet. J. Math. Stat., 41 (2012), 527–536. |
[11] | M. R. Jooyandeh, D. Kiani, M. Mirzakhah, Incidence energy of a graph, MATCH Commun. Math. Comput. Chem., 62 (2009), 561–572. |
[12] | S. K. Ayyaswamy, S. Balachandran, Y. B. Venkatakrishnan, I. Gutman, Signless Laplacian Estrada index, MATCH Commun. Math. Comput. Chem., 66 (2011), 785–794. |
[13] | F. Ashraf, On two conjectures on sum of the powers of signless Laplacian eigenvalues of a graph, Linear Multilinear Algebra, 64 (2016), 1314–1320. https://doi.org/10.1080/03081087.2015.1083525 doi: 10.1080/03081087.2015.1083525 |
[14] | L. You, J. Yang, Notes on the sum of powers of the signless Laplacian eigenvalues of graphs, Ars Combin., 117 (2014), 85–94. |
[15] | S. Akbari, E. Ghorbani, J. H. Koolen, M. R. Oboudi, A relation between the Laplacian and signless Laplacian eigenvalues of a graph, J. Algebraic Combin., 32 (2010), 459–464. https://doi.org/10.1007/s10801-010-0225-9 doi: 10.1007/s10801-010-0225-9 |
[16] | S. Akbari, E. Ghorbani, J. H. Koolen, M. R. Oboudi, On sum of powers of the Laplacian and signless Laplacian eigenvalues of graphs, Electron. J. Combin., 17 (2010), R115. https://doi.org/10.37236/387 doi: 10.37236/387 |
[17] | Ş. B. Bozkurt, D. Bozkurt, On the sum of powers of normalized Laplacian eigenvalues of graphs, MATCH Commun. Math. Comput. Chem., 68 (2012), 917–930. |
[18] | H. Chen, F. Zhang, Resistance distance and the normalized Laplacian spectrum, Discrete Appl. Math., 155 (2007), 654–661. https://doi.org/10.1016/j.dam.2006.09.008 doi: 10.1016/j.dam.2006.09.008 |
[19] | B. Bollobás, P. Erdös, Graphs of extremal weights, Ars Combin., 50 (1998), 225–233. |
[20] | G. P. Clemente, A. Cornaro, New bounds for the sum of powers of normalized Laplacian eigenvalues of graphs, Ars Math. Contemp., 11 (2016), 403–413. https://doi.org/10.26493/1855-3974.845.1b6 doi: 10.26493/1855-3974.845.1b6 |
[21] | J. Li, J. Guo, W. C. Shiu, Ş. B. B. Altındaǧ, D. Bozkurt, Bounding the sum of powers of normalized Laplacian eigenvalues of a graph, Appl. Math. Comput., 324 (2018), 82–92. https://doi.org/10.1016/j.amc.2017.12.003 doi: 10.1016/j.amc.2017.12.003 |
[22] | V. Nikiforov, Merging the $A$- and $Q$-spectral theories, Appl. Anal. Discrete Math., 11 (2017), 81–107. https://doi.org/10.2298/AADM1701081N doi: 10.2298/AADM1701081N |
[23] | S. Liu, K. C. Das, S. Sun, J. Shu, On the least eigenvalue of $A_{\alpha}$-matrix of graphs, Linear Algebra Appl., 586 (2020), 347–376. https://doi.org/10.1016/j.laa.2019.10.025 doi: 10.1016/j.laa.2019.10.025 |
[24] | H. Lin, X. Liu, J. Xue, Graphs determined by their $A_{\alpha}$-spectra, Discrete Math., 342 (2019), 441–450. https://doi.org/10.1016/j.disc.2018.10.006 doi: 10.1016/j.disc.2018.10.006 |
[25] | V. Nikiforov, O. Rojo, A note on the positive semidefiniteness of $A_{\alpha}(G)$, Linear Algebra Appl., 519 (2017), 156–163. https://doi.org/10.1016/j.laa.2016.12.042 doi: 10.1016/j.laa.2016.12.042 |
[26] | X. Liu, S. Liu, On the $A_{\alpha}$-characteristic polynomial of a graph, Linear Algebra Appl., 546 (2018), 274–288. https://doi.org/10.1016/j.laa.2018.02.014 doi: 10.1016/j.laa.2018.02.014 |
[27] | Y. Chen, D. Li, J. Meng, On the second largest $A_{\alpha}$-eigenvalues of graphs, Linear Algebra Appl., 580 (2019), 343–358. https://doi.org/10.1016/j.laa.2019.06.027 doi: 10.1016/j.laa.2019.06.027 |
[28] | S. Liu, K.C. Das, J. Shu, On the eigenvalues of $A_{\alpha}$-matrix of graphs, Discrete Math., 343 (2020), 111917. https://doi.org/10.1016/j.disc.2020.111917 doi: 10.1016/j.disc.2020.111917 |
[29] | L. Wang, X. Fang, X. Geng, F. Tian, On the multiplicity of an arbitrary $A_{\alpha}$-eigenvalue of a connected graph, Linear Algebra Appl., 589 (2020), 28–38. https://doi.org/10.1016/j.laa.2019.12.021 doi: 10.1016/j.laa.2019.12.021 |
[30] | S. Wang, D. Wong, F. Tian, Bounds for the largest and the smallest $A_{\alpha}$ eigenvalues of a graph in terms of vertex degrees, Linear Algebra Appl., 590 (2020), 210–223. https://doi.org/10.1016/j.laa.2019.12.039 doi: 10.1016/j.laa.2019.12.039 |
[31] | D. M. Cardoso, G. Pastén, O. Rojo, Graphs with clusters perturbed by regular graphs$-A_{\alpha}$-spectrum and applications, Discuss. Math. Graph Theory, 40 (2020), 451–466. https://doi.org/10.7151/dmgt.2284 doi: 10.7151/dmgt.2284 |
[32] | X. Li, J. Zheng, A unified approach to the extremal trees for different indices, MATCH Commun. Math. Comput. Chem., 54 (2005), 195–208. |
[33] | H. Lin, J. Xue, J. Shu, On the $A_{\alpha}$-spectra of graphs, Linear Algebra Appl., 556 (2018), 210–219. https://doi.org/10.1016/j.laa.2018.07.003 doi: 10.1016/j.laa.2018.07.003 |
[34] | B. Borovićanin, K. C. Das, B. Furtula, I. Gutman, Bounds for Zagreb indices, MATCH Commun. Math. Comput. Chem., 78 (2017), 17–100. |
[35] | T. Mansour, M. A. Rostami, E. Suresh, G. B. A. Xavier, New sharp lower bounds for the first Zagreb index, Appl. Math.Inform. Mech., 8 (2016), 11–19. https://doi.org/10.5937/SPSUNP1601011M doi: 10.5937/SPSUNP1601011M |
[36] | X. Zhan, Matrix inequalities, Berlin: Springer Press, 2002. |
[37] | M. Bianchi, A. Cornaro, J. L. Palacios, A. Torriero, New bounds of degree-based topological indices for some classes of c-cyclic graphs, Discrete Appl. Math., 184 (2015), 62–75. https://doi.org/10.1016/j.dam.2014.10.037 doi: 10.1016/j.dam.2014.10.037 |
[38] | D. M. Cardoso, G. Pastén, O. Rojo, On the multiplicity of $\alpha$ as an eigenvalue of $A_{\alpha}(G)$ of graphs with pendant vertices, Linear Algebra Appl., 552 (2018), 52–70. https://doi.org/10.1016/j.laa.2018.04.013 doi: 10.1016/j.laa.2018.04.013 |
[39] | X. Huang, H. Lin, J. Xue, The Nordhaus-Gaddum type inequalities of $A_\alpha$-matrix, Appl. Math. Comput., 365 (2020), 124716. https://doi.org/10.1016/j.amc.2019.124716 doi: 10.1016/j.amc.2019.124716 |
[40] | I. Schur, Über eine Klasse von Mittelbildungen mit Anwendungen die Determinanten, Theorie Sitzungsber. Berlin. Math. Gesellschaft, 22 (1923), 9–20. |
[41] | A. W. Marshall, I. Olkin, B. C. Arnold, Inequalities: theory of majorization and its applications, 2 Eds., New York: Springer Press, 2011. https://doi.org/10.1007/978-0-387-68276-1 |
[42] | H. S. Wilf, The eigenvalues of a graph and its chromatic number, J. London Math. Soc., 42 (1967), 330–332. https://doi.org/10.1112/jlms/s1-42.1.330 doi: 10.1112/jlms/s1-42.1.330 |