2012/11/21 by Li, Shuchao, Zhang, Jiajia
#05C50 #15A18 #Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.1211.4924
For two given positive integers p and q with p\leqslant q, we denote \mathscrTnp, q=T: T is a tree of order n with a (p, q)-bipartition. For a graph G with n vertices, let A(G) be its adjacency matrix with eigenvalues λ1(G), λ2(G), ..., λn(G) in non-increasing order. The number Sk(G):=∑i=1nλik(G) (k=0, 1, ..., n-1) is called the kth spectral moment of G. Let S(G)=(S0(G), S1(G),..., Sn-1(G)) be the sequence of spectral moments of G. For two graphs G1 and G2, one has G1\precs G2 if for some k∈ 1,2,...,n-1, Si(G1)=Si(G2) (i=0,1,...,k-1) and Sk(G1)