Abstract
We show that the eigenvalue-free interval for the eccentricity matrix of every threshold graph can be extended from \((-2,-1)\), as shown in [Z. Qiu, Z. Tang, On the eccentricity spectra of threshold graphs. Discrete Appl. Math. 310, 75–85 (2022)], to \((-1-\sqrt{2},-2)\cup (-2,-1)\), and to a larger interval if we exclude certain pathological cases. Our results are based on the fact that the characteristic matrix of the quotient matrix of the eccentricity matrix of a threshold graph is row equivalent to a particular tridiagonal matrix.
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References
Alazemi, A., Anđelić, M., Koledin, T., Stanić, Z.: Eigenvalue-free intervals of distance matrices of threshold and chain graphs. Linear Multilinear Algebra 69, 2959–2975 (2021)
Alazemi, A., Anđelić, M., Simić, S.K.: Eigenvalue location for chain graphs. Linear Algebra Appl. 505, 194–210 (2016)
Anđelić, M., da Fonseca, C.M.: Sufficient conditions for positive definiteness of tridiagonal matrices revisited. Positivity 15, 155–159 (2011)
Cvetković, D., Rowlinson, P., Simić, S.: An Introduction to the Theory of Graph Spectra. Cambridge University Press, Cambridge (2010)
Mahato, I., Gurusamy, R., Kannan, M. Rajesh., Arockiaraj, S.: Spectra of eccentricity matrices of graphs. Discrete Appl. Math. 285, 252–260 (2020)
Qiu, Z., Tang, Z.: On the eccentricity spectra of threshold graphs. Discrete Appl. Math. 310, 75–85 (2022)
Rózsa, P.: On periodic continuants. Linear Algebra Appl. 2, 267–274 (1969)
Wang, J., Lu, M., Belardo, F., Randić, M.: The anti-adjacency matrix of a graph: Eccentricity matrix. Discrete Appl. Math. 251, 299–309 (2018)
Wang, J., Lu, M., Lu, L., Belardo, F.: Spectral properties of the eccentricity matrix of graphs. Discrete Appl. Math. 279, 168–177 (2020)
Wei, W., Li, S., Zhang, L.: Characterizing the extremal graphs with respect to the eccentricity spectral radius, and beyond, Discrete Math., 345, #112686 (2022)
Wei, W., Li, S.: On the eccentricity spectra of complete multipartite graphs, Appl. Math. Comput., 424, #127036 (2022)
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Anđelić, M., Fonseca, C.M.d., Koledin, T. et al. An extended eigenvalue-free interval for the eccentricity matrix of threshold graphs. J. Appl. Math. Comput. 69, 491–503 (2023). https://doi.org/10.1007/s12190-022-01758-3
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DOI: https://doi.org/10.1007/s12190-022-01758-3