DOI QR코드

DOI QR Code

Some New Results on Seidel Equienergetic Graphs

  • Vaidya, Samir K. (Department of Mathematics, Saurashtra University) ;
  • Popat, Kalpesh M. (Department of Master of Computer Application, Atmiya Institute Of Technology & Science)
  • Received : 2018.03.30
  • Accepted : 2019.05.10
  • Published : 2019.06.23

Abstract

The energy of a graph G is the sum of the absolute values of the eigenvalues of the adjacency matrix of G. Some variants of energy can also be found in the literature, in which the energy is defined for the Laplacian matrix, Distance matrix, Commonneighbourhood matrix or Seidel matrix. The Seidel matrix of the graph G is the square matrix in which $ij^{th}$ entry is -1 or 1, if the vertices $v_i$ and $v_j$ are adjacent or non-adjacent respectively, and is 0, if $v_i=v_j$. The Seidel energy of G is the sum of the absolute values of the eigenvalues of its Seidel matrix. We present here some families of pairs of graphs whose Seidel matrices have different eigenvalues, but who have the same Seidel energies.

Keywords

References

  1. C. Adiga, R. Balakrishnan and W. So, The skew energy of a digraph, Linear Algebra Appl., 432(2010), 1825-1835. https://doi.org/10.1016/j.laa.2009.11.034
  2. R. Balakrishnan and K. Ranganathan, A textbook of graph theory, Springer-Verlag, New York, 2000.
  3. S. B. Bozkurt, A. D. Gungor and B. Zhou, Note on distance energy of graphs, MATCH Commun. Math. Comput. Chem., 64(2010), 129-134.
  4. D. Cvetkovic, P. Rowlison and S. Simic, An introduction to the theory of graph spectra, Cambridge university press, Cambridge, 2010.
  5. I. Gutman, The energy of a graph, Ber. Math. Statist. Sekt. Forsch. Graz, 103(1978), 1-22.
  6. I. Gutman, D. Kiani, M. Mirazakhah and B. Zhou, On incidence energy of a graph, Linear Algebra Appl., 431(2009), 1223-1233. https://doi.org/10.1016/j.laa.2009.04.019
  7. I. Gutman and B. Zhou, Laplacian energy of a graph, Linear Algebra Appl., 414(2006), 29-37. https://doi.org/10.1016/j.laa.2005.09.008
  8. W. H. Haemers, Seidel switching and graph energy, MATCH Commun. Math. Comput. Chem., 68(2012), 653-659.
  9. R. A. Horn and C. R. Johnson, Topics In matrix analysis, Cambridge University Press, Cambridge, 1991.
  10. S. Lang, Algebra, Springer-Verlag, New York, 2002.
  11. H. S. Ramane, M. M. Gundloor and S. M. Hosamani, Seidel equienergetic graphs, Bulletin of Mathematical Sciences and Applications, 16(2016), 62-69. https://doi.org/10.18052/www.scipress.com/BMSA.16.62
  12. H. S. Ramane, I. Gutman and M. M. Gundloor, Seidel energy of iterated line graphs of regular graphs, Kragujevac J. Math. 39(1)(2015), 7-12. https://doi.org/10.5937/KgJMath1501007R
  13. X. Li, Y. Shi and I. Gutman, Graph energy, Springer, New York, 2012.