严格对角占优M-矩阵的逆矩阵的无穷大范数的新上界

给出了严格对角占优M-矩阵的逆矩阵的无穷大范数上界新的估计式,进而给出严格对角占优M-矩阵的最小特征值下界的估计式.新估计式改进了已有文献的结果.     

M-矩阵Fan积最小特征值的不等式

给出两个非奇异M-矩阵A和B的Fan积最小特征值下界的新估计式,这些估计式只依赖于两个非奇异M-矩阵的元素,易于计算.数值例子表明,新估计式在一定条件下改进了其他已有的结果.     

M-矩阵特征值的若干估计

M-矩阵是指对一切i(?)j,都有α_(ij)≤0且一切主子式全为正的 n 阶实方阵 A=(α_(ij)).关于 M-矩阵特征值的估计,1975年佟文廷推进了 M-矩阵特征值之实部皆正的一般结果,指出 M-矩阵之绝对值最小的特征值为一正数[1],文[2]对这一特征值的界给出一个估计式,本文首先将这些估计式推广到一般的准 M-矩阵上去,其次从另一方向上讨论了 M-矩阵按模最小特征值的界,最后对不可约 M-矩阵的全部特征值进行了讨论。     

M-矩阵Fan积的特征值下界的新估计

非奇异M-矩阵A与B的Fan积的最小特征值下界T(AB)的估计是矩阵理论研究的重要课题.利用Brauer定理和Gerschgorin定理给出最小特征值下界的新估计式.数值算例表明新估计式在一定条件下改进了Horn和Johnson的结果,同时也改进了其它文献中的一些结果.     

M-矩阵Hadamard积的新不等式(英文)

设A和B是非奇异M-矩阵,给出了关于A和B-1的Hadamard积的最小特征值下界τ(A°B-1)的一个新估计式,该结果改进了文献[4]的结果.     

严格对角占优M-矩阵的逆矩阵的无穷大范数的新上界

<正>1引言M-矩阵不仅是矩阵论和计算数学的重要研究课题之一,而且在物理学、生物学、经济数学等诸多领域有着重要的应用价值.受这些应用背景的影响,最近,许多专家和学者对严格对角占优M-_矩阵A的逆矩阵的无穷大范数‖A~(-1)‖_∞的上界进行了广泛探讨,并给出了一些很好的估计式[1—4].本文继续这个问题的研究,给出了‖A~(-1)‖_∞的上界新的估计式,这些估计式改进了文[2,3,4]中的相应结果.     

M-矩阵Hadamard积的最小特征值下界的新估计式

设B和A是非奇异M-矩阵,给出B和A-1的Hadamard积的最小特征值下界τ（B°A-1）的一个新估计式,理论证明和算例表明,本文所得新估计式改进了现有的一些结果．     

M-矩阵最小特征值下界的新不等式

非奇异M-矩阵B的最小特征值τ(B)的下界是矩阵论中重要的研究课题.利用特征值定位定理,首先给出非负矩阵与M-矩阵的逆矩阵Hadamard积的谱半径上界,进而给出M-矩阵最小特征值下界的新不等式.新不等式只与矩阵的元素有关,易于计算.理论分析和数值例子表明所给结果改进了现有结果.     

非奇异M-矩阵的等价表征

Brualdi 曾给出非奇异 M-矩阵的一个等价表征.本文利用“非零元素链”又给出了非奇异 M-矩阵的一个等价表征,从而改进了 Brualdi 给出的相应结果.     

M-矩阵和逆M-矩阵的Hadamard积(英文)

A=[a_ij]∈M_n和B=[b₍ij(]∈M_n的Hadamard积可表示为AoB=[a_ijb_ij]∈M_n.如果A,B∈M_n是M-矩阵,那么AoB^-1也是M-矩阵.证明了（a）一个非奇异的M-matrix是一对M-矩阵和逆M-矩阵的Hadamard积,同时也证明了（b）一个P-矩阵是两个P-矩阵的Hadamard积.     

Sign determinacy of M-matrix minors

We show that if A is an M-matrix for which the length of the longest simple cycle in its associated undirected graph G(A) is at most 3, then every minor of A has determined sign (nonnegative or nonpositive), independent of the magnitudes of the matrix entries. Consequently, if A and B are M-matrices such that G(A) and G(B) are subgraphs of an undirected graph with longest simple cycle at most 3, then all principal minors of AB are nonnegative.     

对称循环M-矩阵的若干性质

研究实对称循环M-矩阵A的特征值范围、逆矩阵A<'-1>的存在性以及讨论了矩阵(A<'-1>)<'k>的极限性质和(A<'-1>)<'k>的||·||<,2>性质,最后给出了A<'-1>摄动定理.     

M-matrix products having positive principal minors

Sufficient conditions are given for powers and products of M-matrices to have all principal minors positive. Several of these conditions involve directed graphs of the matrices. In particular we show that if A and B are irreducible M-matrices which have longest simple circuit of length two with A+B having no simple circuit longer than three, then the product AB has all principal minors positive.     

M-matrix products having positive principal minors

Sufficient conditions are given for powers and products of M-matrices to have all principal minors positive. Several of these conditions involve directed graphs of the matrices. In particular we show that if A and B are irreducible M-matrices which have longest simple circuit of length two with A+B having no simple circuit longer than three, then the product AB has all principal minors positive.     

判定非奇异M-矩阵的一个直接算法

给出了判定非奇异M-矩阵的一个直接算法.数值例子表明应用该算法可有效地判定一个给定矩阵是否为非奇异M-矩阵.     

A note on a criterion for M-matrix

The aim of this work is to propose a novel method for confirming whether a given matrix is an M-matrix. The proposed method has the advantage of allowing one to deduce whether the matrix whose entry consists of the functional order is an M-matrix.     

Inverse M-matrix completion problem with zeros in the inverse completion

In this paper, we obtain an inverse M-matrix completion, with zeros in the inverse completion, of a noncombinatorially symmetric partial inverse M-matrix, when the associated graph is acyclic without specified paths or, in the other case, when the subgraph induced by the vertices of any cycle or specified path is a clique.     

Convergence of SSOR multisplitting method for an M-matrix

In this paper, we study the convergence of both the multisplitting method and the relaxed multisplitting method associated with SOR or SSOR multisplittings for solving a linear system whose coefficient matrix is anM-matrix.     

M-矩阵的性质与Hadamard-Fisher不等式的注记

主要研究了两个M-矩阵的比较性质与不等式,给出了M-矩阵与逆M-矩阵Hadamard-Fisher不等式等式成立的矩阵结构.