In this paper, we present solutions of two open problems regarding the Wiener index $ W(G) $ of a graph $ G $. More precisely, we prove that for any $ r \geq 2 $, there exist infinitely many graphs $ G $ such that $ W(G) = W(G - \{v_1, \ldots, v_r\}) $, where $ v_1, \ldots, v_r $ are $ r $ distinct vertices of $ G $. We also prove that for any $ r \geq 1 $ there exist infinitely many graphs $ G $ such that $ W(G) = W(G - \{v_i\}) $, $ 1 \leq i \leq r $, where $ v_1, \ldots, v_r $ are $ r $ distinct vertices of $ G $.
Citation: Yi Hu, Zijiang Zhu, Pu Wu, Zehui Shao, Asfand Fahad. On investigations of graphs preserving the Wiener index upon vertex removal[J]. AIMS Mathematics, 2021, 6(12): 12976-12985. doi: 10.3934/math.2021750
In this paper, we present solutions of two open problems regarding the Wiener index $ W(G) $ of a graph $ G $. More precisely, we prove that for any $ r \geq 2 $, there exist infinitely many graphs $ G $ such that $ W(G) = W(G - \{v_1, \ldots, v_r\}) $, where $ v_1, \ldots, v_r $ are $ r $ distinct vertices of $ G $. We also prove that for any $ r \geq 1 $ there exist infinitely many graphs $ G $ such that $ W(G) = W(G - \{v_i\}) $, $ 1 \leq i \leq r $, where $ v_1, \ldots, v_r $ are $ r $ distinct vertices of $ G $.
[1] | A. Dobrynin, R. Entringer, I. Gutman, Wiener Index of Trees: Theory and Applications, Acta Appl. Math., 66 (2001), 211–249. doi: 10.1023/A:1010767517079 |
[2] | E. Estrada, The structure of Complex networks: Theory and Applications, Oxford University press, 2011. |
[3] | W. Gao, W. F. Wang, M. R. Farahani, Topological indices study of molecular structure in anticancer drugs, J. Chem., 2016 (2016), 1–8. |
[4] | M. Knor, S. Majstorović, R. Škrekovski, Graphs preserving Wiener index upon vertex removal, Appl. Math. Comput., 338 (2018), 25–32. |
[5] | M. Knor, S. Majstorović, R. Škrekovski, Graphs whose Wiener index does not change when a specific vertex is removed, Discrete Appl. Math., 238 (2018), 126–132. doi: 10.1016/j.dam.2017.12.012 |
[6] | M. Knor, R. Škrekovski, M. Dehmer, F. Emmert-Streib, Wiener index of line graphs, Quantitative Graph Theory: Mathematical Foundations and Applications, 279 (2014), 301. |
[7] | M. Knor, R. Škrekovski, A. Tepeh, Digraphs with large maximum Wiener index, Appl. Math. Comput., 284 (2016), 260–267. |
[8] | M. Knor, R. Škrekovski, A. Tepeh, Mathematical aspects of Wiener Index, Ars Mathematica Contemporanea, 11 (2016), 327–352. doi: 10.26493/1855-3974.795.ebf |
[9] | C. Liu, A note on domination number in maximal outerplanar graphs, Discrete Applied Mathematics, 293 (2021), 90-94. doi: 10.1016/j.dam.2021.01.021 |
[10] | J. B. Liu, M. Javaid, H. M. Awais, Computing Zagreb Indices of the Subdivision-Related Generalized Operations of Graphs, IEEE Access, 7 (2019), 105479–105488. doi: 10.1109/ACCESS.2019.2932002 |
[11] | M. Liu, B. Liu, A Survey on Recent Results of Variable Wiener Index, MATCH Commun. Math. Comput. Chem., 69 (2013), 491–520. |
[12] | J. B. Liu, J. Zhao, S. Wang, M. Javaid, J. Cao, On the topological properties of the certain neural networks, J. Artif. Intell. Soft, 8 (2018), 257–268. |
[13] | L. Luo, N. Dehgardi, A. Fahad, Lower Bounds on the Entire Zagreb Indices of Trees, Discrete Dyn. Nat. Soc., 2020 (2020), 1–8. |
[14] | L. Šoltés, Transmission in graphs: A bound and vertex removing, Math. Slovaca, 41 (1991), 11–16. |
[15] | W. F. Wang, W. Gao, Second atom-bond connectivity index of special chemical molecular structures, J. Chem., 2014 (2014), 1–8. |
[16] | C. Wan, Z. Shao, N. Dehgardi, R. Khoeilar, M. Soroudi, A. Fahad, Mixed domination and $2$-independence in trees, AIMS Mathematics, 5 (2020), 5564–5571. doi: 10.3934/math.2020357 |
[17] | H. Wiener, Structural Determination of Paraffin Boiling Points, J. Am. Chem. Soc., 69 (1947), 7–20. |
[18] | K. Xu, M. Liu, K. Das, I. Gutman, B. Furtula, A Survey on Graphs Extremal with Respect to Distance Based Topological Indices, MATCH Commun. Math. Comput. Chem., 71 (2014), 461–508. |
[19] | A. Ye, M. I. Qureshi, A. Fahad, A. Aslam, M. K. Jamil, A. Zafar, R. Irfan, Zagreb Connection Number Index of nanotubes and regular Hexagonal lattice, Open Chemistry, 17 (2019), 75–80. doi: 10.1515/chem-2019-0007 |
[20] | D. Zhao, Z. Iqbal, R. Irfan, M. A. Chaudhry, M. Ishaq, M. K. Jameel, A. Fahad, Comparison of irregularity indices of several dendrimers structures, Processes, 7 (2019), 662. doi: 10.3390/pr7100662 |
[21] | J. Zheng, Z. Iqbal, A. Fahad, A. Zafar, A. Aslam, M. I. Qureshi, R. Irfan, Some Eccentricity-based Topological Indices and Polynomials of Poly(EThyleneAmidoAmine)(PETAA) Dendrimers, Processes, 7 (2019), 433. doi: 10.3390/pr7070433 |
[22] | X. Zuo, J. B. Liu, Topological Indices of Certain Transformed Chemical Structures, J. Chem., 2020 (2020), 1–7. |
[23] | J. Bok, N. Jedličková, J. Maxová, On Relaxed Šoltés's Problem, Acta Math. Univ. Comenianae, 88 (2019), 475–480. |