两图同谱的邻接矩阵迹判别法

The Necessary and Sufficient Condition of Two Graphs Cospectrum

证明了下列定理：设A、B分别为困G1＝（V1，E1）与G2=（V2，E2）的邻各矩阵，且V1＝V2＝n，则留G1和G2同语的充分必要条件是tr（Ak）＝tr（Bk），k＝l，2，…，n。

In this paper, We prove the fallowing theorem..Suppose A、B are adjacency matrices ofgraphs G1 = (V1, E1) and G2 = (V2,E2), and V1 = V2 =n, Then the necessary and sufi-cient of graphs G1、G2, cosfectrum is tr (Ak ) =tr(Bk ),k = 1, 2, ..,n 。