Banach空间上有界线性算子的Drazin逆的扰动分析

设X为一复域C上的Banach空间,设T:X→X为一有界线性算子,其指标为k且R(T^k)闭.记T的Drazin逆为T^D.设T=T+δT,则在一定条件下,T^D有简明分解式T^D=T^D(I+δTT^D)^-1=(I+T^DδT)^-1T^D,从而导出了相对误差‖T^D-T^D<     

关于Drazin逆的刻划

Let ■ be a pre-additive category. Assume that ψ:X→X is a morphism of (?). In this paper, we give the necessary and sufficient conditions for ψ to have the Drazin inverse by using the von Neumann regular inverse for the ψk, and extend a result by Puystjens and Hartwig from the group inverse to Drazin inverse.     

A note on the perturbation bounds of W-weighted Drazin inverse

We investigate the perturbation bound for the W-weighted Drazin inverse of a rectangular matrix and present two explicit expressions for the W-weighted Drazin inverse under the one-sided condition, which extends the results in Appl. Math. Comput. 2004;149:423–430.     

关于环上矩阵的群逆与Drazin逆

本文给出了环上一类方阵有群逆，｛１，５｝－道的充要条件及其它们的表式，推广了体（域）上关于群逆的Ｃｌｉｎｅ定理．此外还首次得到了矩阵有Ｄｒａｚｉｎ逆的判别准则及其它的表式．     

带W权Drazin逆的一种新算法

利用矩阵A的带W权Drazin逆的一个性质特征,对任意的矩阵A∈Cm×n,W∈Cn×m,建立了带W权的Drazin逆Ad,w的一种新的表示式,给出了具体的算法步骤,并且在文末给出了算例.     

两个幂等算子线性组合的Drazin逆

利用空间分解的技巧,在条件PQP=QPQ下,得到两个幂等算子P和Q的多线性组合aP+bQ+cPQ+dQP+ePQP的Drazin逆的表达式.     

广义Bott-Duffin逆及加权Drazin逆的若干性质

本文给出了L-零矩阵的广义Bott-Duffin逆及矩阵的加权Drazin逆的若干性质及表达形式．     

Further Results on the Drazin Inverse of Tensors via Einstein Product

In this paper,we give further results on the Drazin inverse of tensors via the Einstein product.We give a limit formula for the Drazin inverse of tensors.By using this formula,the representations for the Drazin inverse of several block tensor are obtained.Further,we give the Drazin inverse of the sum of two tensors based on the representation for the Drazin inverse of a block tensor.     

Banach空间中Drazin逆的新扰动定理

讨论Banach空间中有界线性算子的Drazin逆的扰动问题.利用Jiu Ding在2003年给出的广义Neumann引理,给出关于Drazin逆的一个新扰动定理,并给出误差估计,推广了文献中相应的扰动结果.     

Perturbations of Drazin invertible operators

The necessary and sufficient conditions for the small norm perturbation of a Drazin invertible operator to be still Drazin invertible and the sufficient conditions for the finite rank perturbation of a Drazin invertible operator to be still Drazin invertible are established.     

一类矩阵的Drazin逆

本文得到了一类环上矩阵Ｄｒａｚｉｎ逆的一个定理：设Ｎ表有单位元环Ｒ中零元、可逆元集合与Ｒ的中心Ｚ（Ｒ）的交集，Ｍ表Ｒ的子域与Ｚ（Ｒ）的交集，Ａ∈Ｒｎ×ｎ．若ｆ（λ）＝ｃλｋ（１－λｑ（λ））是Ａ的化零多项式，其中ｑ（λ）的系数属于Ｎ，且ｃ∈Ｎ，则Ａ的Ｄｒａｚｉｎ逆存在，且Ｘ＝Ａｋ［ｑ（Ａ）］ｋ＋１是Ａ的唯一的一个Ｄｒａｚｉｎ逆．     

Representations and properties of the W-Weighted Drazin inverse

Several new representations of the W-weighted Drazin inverse are introduced. These representations are expressed in terms of various matrix powers as well as in terms of matrix products involving the Moore–Penrose inverse and the usual matrix inverse. Also, the properties of various generalized inverses which arise from derived representations are investigated. The computational complexity and efficiency of the proposed representations are considered. Representations are tested and compared among themselves in a substantial number of randomly generated test examples.     

On the Drazin index of regular elements

It is known that the existence of the group inverse a ^# of a ring element a is equivalent to the invertibility of a ² a ⁻ + 1 − aa ⁻, independently of the choice of the von Neumann inverse a ⁻ of a. In this paper, we relate the Drazin index of a to the Drazin index of a ² a ⁻ + 1 − aa ⁻. We give an alternative characterization when considering matrices over an algebraically closed field. We close with some questions and remarks.      

Banach空间中线性算子的Drazin广义逆的表示

1981年,1985年,2000年,乔三正、蔡东汉、魏益民分别给出Drazin广义逆不同形式的表示．本文将对上述结果进行推广,给出Drazin广义逆的统一表示,使上述三个结果均成为本文主要结果的特例．在本文主要结果的基础上,利用算子谱理论,给出Drazin广义逆的一种逼近形式的表示,同时给出逼近解的估计．此结果推广了蔡东汉、魏益民的相应结果．     

有界线性算子和的Drazin逆表示

本文讨论了两个有界线性算子和的Drazin可逆性及其表达式.在PQ~3=0,P~2Q=0,QPQ~2=0的条件下,采用预解式的Laurent展开方法,证明了P+Q是Drazin可逆的,并得到了P+Q的Drazin逆的表达式.同时,还确定出P+Q的指标的范围ind(P+Q)≤2t+r+s—1,给出数值算例说明结论的有效性.     

Some results on the Drazin inverse of anti-triangular matrices

Abstract

The representations for the Drazin inverse of anti-triangular matrices are obtained under some conditions. Applying these representations, we give a necessary condition for a class of block matrices to have signed Drazin inverse.     

有界线性算子的Drazin逆的逆序律

该文讨论了两个有界线性算子乘积的Drazin可逆性及其逆序律,分别在P与PQP可交换(即P²QP=PQP²)和Q与QPQ可交换(即Q²PQ=QPQ²)等条件下,采用空间分解的方法得到了PQ的Drazin可逆性及其逆序律(PQ)^D=Q^DP^D成立的等价条件.     

On the Generalized Drazin Inverse and Generalized Resolvent

We investigate the generalized Drazin inverse and the generalized resolvent in Banach algebras. The Laurent expansion of the generalized resolvent in Banach algebras is introduced. The Drazin index of a Banach algebra element is characterized in terms of the existence of a particularly chosen limit process. As an application, the computing of the Moore-Penrose inverse in >C ^*-algebras is considered. We investigate the generalized Drazin inverse as an outer inverse with prescribed range and kernel. Also, 2 × 2 operator matrices are considered. As corollaries, we get some well-known results.     

环上幂等矩阵线性组合的Drazin逆

给出了环R上幂等矩阵P,Q满足不同条件:(1)PQP=0;(2)PQP=PQ;(3)PQ=QP;(4)PQP=P时P+aQ的Drazin逆的表达式,推广了一些已有的结论.     

The Drazin inverse in an arbitrary semiring

In this article, we investigate the Drazin invertibility for the elements of an arbitrary semiring. We give necessary and sufficient conditions for the existence and expressions of the Drazin inverse of an element in an arbitrary semiring. Moreover, we consider the product paq under some additional necessary conditions for which the Drazin inverse of the product paq exists.