【摘要】 设 M( G)是简单无向图 G的关联矩阵 ,A是 M( G)的可逆子矩阵 ,γ( A)是逆矩阵 A- 1中非零元素的个数 .获得了求逆矩阵 A- 1的一种图论方法 ,并且得到了γ( A)的精确上下界以及达到上下界时子矩阵 A的图论刻划更多还原

【Abstract】 Let M(G) be the incident matrix of a simply undirected graph. Let γ(A) denote the number of nonzero entries in the inverse of an invertible submatrix A of M(G). In this paper, we first obtain a simple and effective method for solving the inverse of an invertible submatrix of M(G), then we obtain the tight upper and lower bounds of γ(A), meanwhile all extreme submatrice which reach bounds are characterized.更多还原