Abstract
In this paper, we study the signless Laplacian spectral Turán type problem in terms of the size, obtain sharp upper bounds on the signless spectral radius of \(C_3\) (\(C_4\))-free graphs with given size and minimum degree \(\delta \ge 2\), and characterize the corresponding extremal graphs completely.
Similar content being viewed by others
Data Availability
Our manuscript has no associated data.
References
Brualdi, R.A., Hoffman, A.J.: On the spectral radius of \((0,1)\)-matrices. Linear Algebra Appl. 65, 133–146 (1985)
Chen, W., Wang, B., Zhai, M.: Signless Laplacian spectral radius of graphs without short cycles or long cycles. Linear Algebra Appl. 645, 123–136 (2022)
Cvetković, D., Rowlinson, P., Simić, S.K.: Eigenvalue bounds for the signless Laplacian. Publ. Inst. Math. (Beograd) 81(95), 11–27 (2007)
Cvetković, D., Simić, S.: Towards a spectral theory of graphs based on the signless Laplacian, I. Publ. Inst. Math. (Beograd) 85(99), 19–33 (2009)
Das, K.C.: The Laplacian spectrum of a graph. Comput. Appl. Math. 48, 715–724 (2004)
Feng, L., Yu, G.: On three conjectures involving the signless Laplacian spectral radius of graphs. Publ. Inst. Math. (Beograd) 85(99), 35–38 (2009)
Gao, M., Lou, Z., Huang, Q.: A sharp upper bound on the spectral radius of \(C_5\)-free /\(C_6\)-free graphs with given size. Linear Algebra Appl. 640, 162–178 (2022)
Guo, S.G., Zhang, R.: Sharp upper bounds on the \(Q\)-index of (minimally) \(2\)-connected graphs with given size. Discrete Appl. Math. 320, 408–415 (2022)
Hong, Y., Zhang, X.D.: Sharp upper and lower bounds for largest eigenvalue of the Laplacian matrices of trees. Discrete Math. 296, 187–197 (2005)
Jia, H., Li, S., Wang, S.: Ordering the maxima of \(L\)-index and \(Q\)-index: graphs with given size and diameter. Linear Algebra Appl. 652, 18–36 (2022)
Li, J.S., Zhang, X.D.: On the Laplacian eigenvalues of a graph. Linear Algebra Appl. 285, 305–307 (1998)
Lin, H., Ning, B., Wu, B.Y.D.R.: Eigenvalues and triangles in graphs. Combin. Probab. Comput. 30, 258–270 (2021)
Lou, Z., Guo, J.M., Wang, Z.: Maxima of \(L\)-index and \(Q\)-index: graphs with given size and diameter. Discrete Math. 344, 112533 (2021)
Merris, R.: A note on Laplacian graph eigenvalues. Linear Algebra Appl. 285, 33–35 (1998)
Nikiforov, V.: Some inequalities for the largest eigenvalue of a graph. Combin. Probab. Comput. 11, 179–189 (2002)
Nikiforov, V.: The maximum spectral radius of \(C_4\)-free graphs of given order and size. Linear Algebra Appl. 430, 2898–2905 (2009)
Nikiforov, V.: The spectral radius of graphs without paths and cycles of specified length. Linear Algebra Appl. 432, 2243–2256 (2010)
Nosal, E.: Eigenvalues of Graphs, Master Thesis, University of Calgary (1970)
Oliveira, C.S., de Limab, L.S., de Abreu, N.M.M., Hansen, P.: Bounds on the index of the signless Laplacian of a graph. Discrete Appl. Math. 158, 355–360 (2010)
Rowlinson, P.: On the maximal index of graphs with a prescribed number of edges. Linear Algebra Appl. 110, 43–53 (1988)
Wang, Z., Guo, J.M.: Maximum degree and spectral radius of graphs in terms of size. arXiv:2208.13139
Yu, G.L., Wu, Y.R., Shu, J.L.: Sharp bounds on the signless Laplacian spectral radii of graphs. Linear Algebra Appl. 603, 683–687 (2011)
Zhai, M., Lin, H., Shu, J.: Spectral extrema of graphs with fixed size: cycles and complete bipartite graphs. Eur. J. Combin. 95, 103322 (2021)
Zhai, M.Q., Xue, J., Liu, R.: An extremal problem on \(Q\)-spectral radii of graphs with given size and matching number. Linear Multilinear Algebra 70, 5334–5345 (2022)
Zhai, M., Xue, J., Lou, Z.: The signless Laplacian spectral radius of graphs with a prescribed number of edges. Linear Algebra Appl. 603, 154–165 (2020)
Zhang, R., Guo, S.G.: Ordering graphs with given gize by their signless Laplacian spectral radii. Bull. Malays. Math. Sci. Soc. 45, 2165–2174 (2022)
Acknowledgements
The authors are grateful to the referees for their careful reading and many valuable suggestions.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
Authors declare that they have no competing interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supported by the National Natural Science Foundation of China (nos. 12071411, 12171222).
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Guo, SG., Zhang, R. Maxima of the Q-Spectral Radius of \(C_3\) (\(C_4\))-Free Graphs with Given Size and Minimum Degree \(\delta \ge 2\). Graphs and Combinatorics 39, 102 (2023). https://doi.org/10.1007/s00373-023-02685-1
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/s00373-023-02685-1