C~*代数上保持不定正交性的线性映射

设A和B是含单位元的C~*代数,s∈A和t∈B是可逆自伴元,对任意的x∈A及z∈B,定义x~+=s~(-1)x~*s,z~+=t~(-1)z~*t。假定A是实秩零的并且Φ:A→B是有界线性满射。证明了对任意的 都成立的充要条件是Φ(1)可逆,Φ(1)~+Φ(1)=Φ(1)Φ(1)~+∈Z(B)(B的中心),并且存在从A到B上的满+同态Ψ,使得对所有的x∈A都有Φ(x)=Φ(1)Ψ(x)成立。对于一般C~*代数上保正交性的线性映射Φ,在假定Φ(1)可逆的条件下,也得到类似的结果。     

主理想整环上保对合矩阵的线性映射

设R是特征不为2的交换主理想整环,Mn（R）表示R上n阶全矩阵模,本文基底生成元的方法刻划Mn（R）上保对合矩阵的R-线性映射的形式。     

C*代数上保持不定正交性的线性映射

设A和B是含单位元的C*代数,s∈A和t∈B是可逆自伴元.对任意的x∈A及z∈B,定义x+=s-1x*s,z+=t-1z*t.假定A是实秩零的并且φA→B是有界线性满射.证明了对任意的x,y∈A,x+y=0 φ(x)+φ(y)=0且xy+=0φ(x)φ(y)+=0都成立的充要条件是φ(1)可逆,φ(1)+φ(1)=φ(1)φ(1)+∈Z(B)(B的中心),并且存在从A到B上的满+同态ψ,使得对所有的x∈A都有φ(x)=φ(1)ψ(x)成立.对于一般C*代数上保正交性的线性映射φ,在假定φ(1)可逆的条件下,也得到类似的结果.     

Banach空间有界线性算子强连续双半群

本文在Ｂａｎａｃｈ空间上研究单参数有界线性算子族－强连续双半群。     

PID环上矩阵模的保秩1映射及应用

设Ｒ为含１主理想整环（简记为ＰＩＤ），本文刻划了矩阵模Ｍｎ（Ｒ）上保秩１线性映射的形式；作为其应用，给出了域上矩阵空间的保线性群及Ｍｎ（Ｒ）上保非零行列线性映射的形式，即它们为：Ｔ（Ｘ）＝ＰＸＱ，Ａ↑Ｘ∈Ｍｎ（Ｒ），或Ｔ（Ｘ）＝ＰＸｔＱ，Ａ↑Ｘ∈Ｍｎ（Ｒ）。其中ｄｅｔ（ＰＱ）≠０。     

Banach空间中线性算子的Tseng度量广义逆

在 Ｂａｎａｃｈ空间中,利用 Ｂａｎａｃｈ几何方法及度量投影算子,将 Ｅ．Ｈ．Ｍｏｏｒｓ的学生,曾远荣（Ｙ．Ｙ． Ｔｓｅｎｇ）在 Ｈｉｌｂｅｒｔ空间中为线性算子引入的 Ｔｓｅｎｇ广义道,推广到 Ｂａｎａｃｈ空间,引入 Ｔｓｅｎｇ度量广义逆（此时的 Ｔｓｅｎｇ度量广义逆一般为齐性算子,而非线性算子）,利用 Ｂａｎａｃｈ空间对偶映射与广义正交分解定理给出 Ｔｓｅｎｇ度量广义道存在的充分必要条件．讨论了最大Ｔｓｅｎｇ度量广义逆在最优化,控制论及微分方程不适定问题有着直接应用的一些基础性质．     

METRIC GENERALIZED INVERSE OF LINEAR OPERATOR IN BANACH SPACE＊＊＊

The Moore-Penrose metric generalized inverse T of linear operator T in Banach space is systematically investigated in this paper. Unlike the case in Hilbert space, even T is a linear operator in Banach Space, the Moore-Penrose metric generalized inverse T is usually homogeneous and nonlinear in general. By means of the methods of geometry of Banach Space, the necessary and sufficient conditions for existence, continuitv, linearity and minimum property of the Moore-Penrose metric generalized inverse T will be given, and some properties of T will be investigated in this paper.     

B(X)上保持算子拟仿射性或值域稠性的线性映射

设X和y是无限维的复Banach空间,φ是从B(X)到B(y)保单位的线性满射.本文证明了φ双边保算子的拟仿射性当且仅当φ为同构或反同构;φ双边保算子的值域稠性当且仅当φ是同构.     

B(X)上保持算子拟仿射性或值域稠性的线性映射

设X和Y是无限维的复Banach空间,Φ是从B(X)到B(Y)保单位的线性满射.本文证明了Φ双边保算子的拟仿射性当且仅当Φ为同构或反同构;Φ双边保算子的值域稠性当且仅当Φ是同构.     

ODEs IN BANACH SPACES AND FIXED POINTS OF WEAKLY INWARD MAPS

（韩志清）ＯＤＥｓＩＮＢＡＮＡＣＨＳＰＡＣＥＳＡＮＤＦＩＸＥＤＰＯＩＮＴＳＯＦＷＥＡＫＬＹＩＮＷＡＲＤＭＡＰＳ￥ＨａｎＺｈｉｑｉｎｇ（Ｄｅｐｔ．ｏｆＭａｔｈ．，ＳｈａｎｄｏｎｇＵｎｉｖ，Ｊｉｎａｎ２６６０７１，Ｃｈｉｎａ）Ａｂｓｔｒａｃｔ：Ｔｈｉｓｐ...     

交换整环上的上三角矩阵保对合的线性算子

本文刻划了交换整环Ｒ上的上三角长阵的Ｒ－代数Ｆｎ（Ｒ）的保对合的可逆线性算子，由此又确定了Ｆｎ（Ｒ）的保立方幂等的可逆线性算子。     

On K_0-groups of operator algebras on Banach spaces

This paper merges some classifications of G-M-type Banach spaces simplifically, discusses the condition of K0(B(X)) = 0 for operator algebra B(X) on a Banach space X, and obtains a result to improve Laustsen's sufficient condition, gives an example to show that X ≈ X2 is not a sufficient condition of K0(B(X)) = 0.     

Prediction Operators in Banach Ideal Spaces

A necessary and sufficient condition for an operator in a Banach ideal space to be a prediction operator is given.     

一类非线性算子方程拟Galerkin逼近意义下的可解性

对非线性算子方程 x+KF x=y,本文构造了一种新的不同于 Galerkin逼近的另一种逼近方程 ,并证明了在此逼近意义下上述方程是逼近可解的     

B(X)上的保k次幂线性映射

设Ｘ 为Ｂａｎａｃｈ 空间,Ｂ（Ｘ）为Ｘ 上有界线性算子全体组成的代数,本文给出了Ｂ（Ｘ）上保ｋ 次幂弱连续线性满射的完全刻划．     

ADJACENCY PRESERVING MAPS ON THE SPACE OF SELF-ADJOINT OPERATORS

§1. Introduction and Statement of ResultsThe study of the geometry of matrices was initiated by Hua [11–18] in the middle oftwenty century. In this geometry, the points of the space are a certain kind of matricesof a given size (rectangular matrices, symmetric matrices, Hermitian matrices, etc.). Witheach such space of matrices, we associate a group of motions. The main problem is tocharacterize this group by a geometric invariant called adjacency (see [23]). Recently, someauthors have gen…     

在一般Gauss─Markoff模型下线性变换保最佳线性最小偏倚估计

在一般Ｇａｕｓｓ－Ｍａｒｋｏｆｆ模型｛Ｙ，Ｘβ，Ｖ｝下，设Ｆ是一个适当阶矩阵，Ｃ为任意适当维向量，本文找到了ＡＹ是Ｃ＇β的最小偏倚估计的充分必要条件及ＡＹ是Ｃ＇β的最佳线性最小偏倚估计的充要条件．在以概率１意义下，证明了对于所有适当维向量Ｃ，Ｃ＇β的最佳线性最小偏倚估计能被表示成ＦＹ的线性函数的充要条件，且在此条件下，线性变换保最佳线性最小偏倚估计．     

Small into isomorphisms on uniformly smooth spaces

Let X be a uniformly smooth infinite dimensional Banach space, and (Ω,Σ,μ) be a σ-finite measure space. Suppose that T:X→L∞(Ω,Σ,μ) satisfies

(1−ε)‖x‖?‖Tx‖?‖x‖,∀x∈X,     

A higher rank version of Kitai's theorem

We prove that each linear action of on an infinite-dimensional Banach space generated by compact operators cannot be hypercyclic. This result generalizes a theorem of Kitai for the case of Z₊ actions. Contrary to the case of infinite dimension, a hypercyclic action of on C is given.     

On Concave Operators

We prove that a u0-concave operator can include other concave operators, and derive a sufficient and necessary condition for the existence and uniqueness of the fixed point of a kind of u0-concave operator under a weaker condition.