Amitsur定理和Regev定理的推广

本文将PI一环论中关于恒等式和中心多项式的Amitsur定理和Regev定理同时由域推广到无零因子环,得到无零因子环上全矩阵环的两个相应定理。     

形式三角矩阵环的零因子图

本文研究了形式三角矩阵环的零因子结构与零因子图的问题.利用零因子的性质及交换环零因子图的有关结论及分类讨论的方法,获得了形式三角矩阵环的零因子图直径为2的充要条件,推广了有限交换环的零因子图的相关结果.     

一类仅含双侧零因子的有限环

文[1]指出,若环 R 含 n(n>1)个左(右)零因子,则|R|≤n~2.文[2、3]研究了含n(n>1)个左(右)零因子且|R|=n~2的环,本文目的是讨论不含单侧零因子,含且只含双侧零因子的有限环,文中所得结果是[2、3]中相应结论的推广。定义 环中元素 a 称为一个左(右)零因子当且仅当存在元素 x≠0使 ax=0(xa=0);若 a 是左(右)零因子但不是右(左)零因子则称 a 为单侧左(右)零因子;双侧零因子简     

交换环上的形式矩阵环的零因子和零因子图（英文）

本文主要研究交换环R上的形式矩阵环M_n(R;{S_(ijk)})的零因子和零因子图.首先给出了环上形式线性方程组的概念,并且得到了交换环上形式齐次线性方程组有非平凡解的充分必要条件.然后证明了A是M_n(R;{S_(ijk)})的零因子当且仅当A的行列式是R的零因子当且仅当A是R[A]的零因子.最后研究了交换环R上的形式矩阵环M_n(R;{S_(ijk)})的零因子图的性质.     

环的Armendariz性

研究了一个环何时具有Armendariz性．使用环论的一般方法,证明了在一定条件下商环、具有一对零同态的Morita Context环以及映射环是Armendariz环,推广了已有的某些结果．     

除环上左线性方程组的反问题

推广并改进了实数域上线性方程组的反问题及其一系列结果，解决了除环上左线性方程组更具广泛性的一类反问题，给出了此类反问题有（斜）自共轭解及（半）正定自共轭解的充要条件及其解集结构．     

每一个元素都是左零因子之环

本文引进左(右)零因子环的概念,它们是一类无单位元的环.我们称一个环为左(右)零因子环,如果对于任何 $a \in R$,都有$r_R (a) \neq 0~(l_R(a)\neq 0)$,而称一个环为强左(右)零因子环,如果$r_R(R)\neq 0~(l_R(R)\neq 0)$.Camillo和Nielson称一个环$R$为右有限零化环(简称RFA-环),如果$R$的每一个有限子集都有非零的右零化子.本文给出左零因子环的一些基本例子,探讨强左零因子环和RFA-环的扩张,并给出它们的等价刻画.     

群环Z_nG的零因子图的性质,Ⅲ

环的零因子图是20世纪90年代才兴起的一个数学研究方向.环上的零因子图的研究,刻画了环的零因子的结构,这对理解环结构本身具有重要意义.群环是群论和环论的交汇点之一.对它的研究在环论,群论及伽罗华理论等学科领域都有重要的意义.主要讨论了群环Z_nG的零因子图的性质,对群环Z_nG的零因子图的围长,平面性,直径给出了较为具体的刻画,其中G为非循环的有限交换群.     

零可换环的一些性质

本文刻画了零可换环的一些性质,同时将交换环上的一些结果推广到零可换环上.对于零可换环R证明了(1)R是强正则环当且仅当R中每个为零化子的本质左理想是左GP-内射模或R中存在一个极大左理想K,使得K中每个元素的零化子是左GP-内射模;(2)R是GPP-环当且仅当R是拟π-正则的GPF-环.     

零可换环的一些性质

本文刻画了零可换环的一些性质,同时将交换环上的一些结果推广到零可换环上.对于零可换环R 证明了: (1)R是强正则环当且仅当R中每个为零化子的本质左理想是左GP.内射模或R中存在一个极大左理想K,使得K中每个元索的零化子是左GP-内射模; (2)R是GPP-环当且仅当R是拟π-正则的GPF-环.     

关于域上矩阵广义逆的加法映射

假设F是特征不为2的域,令Mn(F)是F上n×n矩阵的集合.本文证明了f是Mn(F)到自身的矩阵{1}-逆或{1,2}-逆的加法保持算子当且仅当f有:(a)f=0;(b)f(A)=εPAτP-1对任意A∈Mn(F),其中P∈GLn(F),τ-为域F的某个单自同态且x(1)=1,ε=±1;(c)f(A)=εP(Aτ)TP-1对于任意A∈Mn(F),其中τ,ε,P如(b)中一样意义.     

Invertible linear maps preserving {1}-inverses of matrices over PID

Let R be a PID,chR = 2,n > 1, M_n(R) be then xn full matrix algebra over R.f denotes any invertible linear map preserving {1}-inverses from M_n(R) to itself. In this paper, we have proven thatf is an invertible linear map on M_n(R) preserving {1}-inverses if and only iff satisfies any one of the following two conditions: (i) there exists a matrixP ? GL _n(R) such thatf(A) =PAP ^?1 for allA ? M _n(R), (ii) there exists a matrixP ? GL _n(R) such thatf(A) =PA ^t P^?1 forA ? M _n(R).     

ON THE ｛2｝－INVERSE AND SOME ORDERING PROPERTIES OF NONNEGATIVE DEFINITE MATRICES

ＥＲＫＫＩＰ．ＬＩＳＫＩ（ＤｅｐｅｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃａｌＳｃｉｅｎｃｅｓ，ＵｎｉｖｅｒｓｉｔｙｏｆＴａｍｐｅｒｓ，Ｆｉｎｌａｎｄ）ＷＡＮＧＳＯＮＧＧＵＩ（王松桂）（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓ，Ｂｅｉ...     

On generalized inverses of Boolean Matrices

Generalized inverses of Boolean Matrices are defined and the general form of matrices having generalized inverses is determined. Some structure theorems are proved, from which, some known results are obtained as corollaries. An algorithm to compute a generalized inverse of a matrix, when it exists, is given. The existence of various types of g-inverses is also investigated. All the results are obtained first for the {0,1}-Boolean algebra and then extended to an arbitrary Boolean algebra.     

Integer generalized inverses of incidence matrices

Graphical procedures are used to characterize the integral {1}- and {1, 2}-inverses of the incidence matrix A of a digraph, and to obtain a basis for the space of matrices X such that AXA = 0. These graphical procedures also produce the Smith canonical form of A and a full rank factorization of A using matrices with entries from {-1, 0, 1}. It is also shown how the results on incidence matrices of oriented graphs can be used to find generalized inverses of matrices of unoriented bipartite graphs.     

The {2}-inverse with applications in statistics

An inverse G of a given matrix A which satisfies the property GAG = G is known as a {2}-inverse. This paper presents a three-phase inversion procedure for which the {2}-inverse is a special case. We present the geometry of {2}-inverses and show that, starting from {2}-inverses, various types of generalized inverses can be derived. Two examples of the occurrence of {2}-inverses in statistics are given: one concerning the constrained least-squares estimator, the other concerning a necessary and sufficient condition for a quadratic form of singular multivariate normal variates to follow a chi-square distribution.     

有限局部环上对称矩阵的计数定理(I)

设$A_{n}(R)$是有限局部环$Z/p^{k}Z$上$n$阶对称矩阵的集合, 这里$n\geq 2$. $p$是大于$2$素数, $p\equiv1({\rm mod}4)$ 且$k>1$. 通过确定有限局部环$Z/p^{k}Z$上对称矩阵的标准型, 计算出$A_{n}(R)$在线性群${\rm GL}_{n}(R)$作用下的轨道数, 从而计算出由特定对称矩阵确定的正交群的阶以及与特定对称矩阵在同一轨道的对称矩阵的阶.     

Comments on some recent results concerning {2, 3} and {2, 4}-generalized inverses

We give a comment on some recent results concerning the representations of generalized {2, 3} and {2, 4}-inverses. Shorter proofs of some previous results are presented.     

More on generalized inverses of partitioned matrices with Banachiewicz–Schur forms

Necessary and sufficient conditions are derived for a 2-by-2 partitioned matrix to have {1}-, {1,2}-, {1,3}-, {1,4}-inverses and the Moore–Penrose inverse with Banachiewicz–Schur forms. As applications, the Banachiewicz–Schur forms of {1}-, {1,2}-, {1,3}-, {1,4}-inverses and the Moore–Penrose inverse of a 2-by-2 partitioned Hermitian matrix are also given.     

On linear operators strongly preserving invariants of Boolean matrices

Let U _k be the general Boolean algebra and T a linear operator on M _m,n (U _k ). If for any A in M _m,n (U _k ) (M _n (U _k ), respectively), A is regular (invertible, respectively) if and only if T(A) is regular (invertible, respectively), then T is said to strongly preserve regular (invertible, respectively) matrices. In this paper, we will give complete characterizations of the linear operators that strongly preserve regular (invertible, respectively) matrices over U _k . Meanwhile, noting that a general Boolean algebra U _k is isomorphic to a finite direct product of binary Boolean algebras, we also give some characterizations of linear operators that strongly preserve regular (invertible, respectively) matrices over 169-7 _k from another point of view.