双圈图的邻接矩阵的奇异性

The Singular of the Adjacency Matrix of Graphs with Bicycle

连通的双圈图(即边数比顶点数多一个的连通简单图)恰有3种类型,其中2种类型的图的邻接矩阵的奇异性问题业已解决.现给出第三种类型的双圈图的邻接矩阵是奇异的充要条件.

There are three types in the connected bicycle graphs （the number of the edges is the number of the points adding one） .The singular of the adjacency matrix of two of them has been studied . The Iff conditions of the singular of the adjacency matrix of the third type of the bicycle graphs is determined in this article.