Abstract
Let G be a graph of order n and let λ 1, λ 2, …, λ n be its eigenvalues. The Estrada index [2] of G is defined as EE = EE(G) = \( \sum\limits_{i = 1}^n {e^{\lambda _i } } \). In this paper, new bounds for EE are established, as well as some relations between EE and graph energy E.
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Supported by the National Natural Science Foundation of China (10771080), by the Fund of Fuzhou University (XRC-0956), and by the Natural Science Foundation of Fujian Province (2010J05005).
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Liu, Jp., Liu, Bl. Bounds of the Estrada index of graphs. Appl. Math. J. Chin. Univ. 25, 325–330 (2010). https://doi.org/10.1007/s11766-010-2237-6
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DOI: https://doi.org/10.1007/s11766-010-2237-6