Spectral characterization of new classes of multicone graphs

Authors

DOI:

https://doi.org/10.24193/subbmath.2017.3.01

Keywords:

Adjacency spectrum, Laplacian spectrum, DS graph.

Abstract

This paper deals with graphs that are known as multicone graphs. A multicone graph is a graph obtained from the join of a clique and a regular graph. Let w, l, m be natural numbers and k is a natural number. It is proved that any connected graph cospectral with multicone graph Kw 9 mECP k is determined by its adjacency spectra as well as its Laplacian spectra, where ECP k = 3k , 3k , ..., 3. Also, we show that complements of some of these multicone graphs are determined by their adjacency spectra. Moreover, we prove that any connected graph cospectral with these multicone graphs must be perfect. Finally, we pose two problems for further researches.

Mathematics Subject Classification (2010): 05C50.

References

Abdian, A.Z., Mirafzal S.M., On new classes of multicone graphs determined by their spectrums, Alg. Struc. Appl., 2(1)(2015), 21-32.

Abdollahi, A., Janbaz, S., Oubodi, M., Graphs Cospectral with A Friendship Graph Or its Complement, Trans. Comb., 2(4)(2013), 37-52.

Abdollahi, A., Janbaz, S., Connected graphs cospectral with a friendship graph, Trans. Comb., 3(2)(2014), 17-20.

Biggs, N.L., Algebraic Graph Theory, Second ed., Cambridge University Press, Cam- bridge, 1933.

Cvetkovi´c, D., Rowlinson, P., Simi´c, S., An Introduction to the Theory of graph Spectra, London Mathematical Society Student Texts, 75, Cambridge University Press, Cam- bridge, 2010.

Cvetkovi´c, D., Doob, M., Simi´c, S.K., Generalized line graphs, J. Graph Theory, 5(4)(1981), 385-399.

Cioaba, S.M., Haemers, W.H., Vermette, J.R., Wong, W., The graphs with all but two eigenvalues equal to ±1, Journal of Algebraic Combinatorics, 44(3)(2013), 887-897.

Das, K.C., Proof of conjectures on adjacency eigenvalues of graphs, Discret. Math., 313(1)(2013), 19-25.

Erdo¨s, P., R´eyni A., S´os V.T., On a problem of graph theory, Sci. Math. Hungarica, 1(966), 215-235.

Godsil, C.D., Royle, G., Algebraic Graph Theory, Graduate Texts in Mathematics 207, 2001.

Gallian, J.A., A dynamic survey of graph labeling, Electron. J. Combin., 16(6)(2009), 1-219.

Kanauer, U., Algebraic Graph Theory, Morphisms, Monoids and Matrices, 41, Walter de Gruyter, 2011.

Mohammadian, A., Tayfeh-Rezaie, B., Graphs with four distinct Laplacian eigenvalues, Journal of Algebraic Combinatorics, 34(4)(2011), 671-682.

Omidi, G.R., On graphs with largest Laplacian eignnvalues at most 4, Australasian J. Combin., 44(2009), 163-170.

van Dam E.R., Haemers, W.H., Which graphs are determined by their spectrum?, Linear Alg. Appl., 373(2003), 241-272.

van Dam, E.R., Haemers, W.H., Developments on spectral characterizations of graphs, Discrete Math., 309(2009), 576-586.

Wang, J., Belardo, Huang, Q., Borovicanin, B., On the two largest Q-eigenvalues of graphs, Discrete Math., 310(2010), 2858-2866.

Wang, J., Zhao, H., Huang, Q., Spectral characterization of multicone graphs, Czechoslo- vak Math. J., 62(1)(2012), 117-126.

West, D.B., Introduction to Graph Theory, Upper Saddle River, Prentice Hall, 2001.

Downloads

Published

2017-09-30

How to Cite

MIRAFZAL, S. M., & ZEYDI ABDIAN, A. (2017). Spectral characterization of new classes of multicone graphs. Studia Universitatis Babeș-Bolyai Mathematica, 62(3), 275–286. https://doi.org/10.24193/subbmath.2017.3.01

Issue

Section

Articles