On Spectrum of I-graphs and Its Ordering with Respect to Spectral Moments
نویسندگان
چکیده
Suppose G is a graph, A(G) its adjacency matrix, and μ1(G)≤ μ2(G) ≤ ·· · ≤ μn(G) are eigenvalues of A(G). The numbers Sk(G) = n ∑ i=1 μk i (G), 0 ≤ k ≤ n− 1 are said to be the k−th spectral moment of G and the sequence S(G) = (S0(G),S1(G), · · · ,Sn−1(G)) is called the spectral moments sequence of G. For two graphs G1 and G2, we define G1 ≺S G2, if there exists an integer k, 1≤ k≤ n−1, such that for each i, 0≤ i≤ k−1, Si(G1) = Si(G2) and Sk(G1)< Sk(G2). The I−graph I(n, j,k) is a graph of order 2n with the vertex and edge sets
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