无穷矩阵拓扑代数的理想(Ⅰ)(英文)

本文给出了所有弱紧算子 ,强紧算子 ,Mackey紧算子 ,构成无穷矩阵拓扑下相同紧集的特征的刻画 .     

一类无穷矩阵代数的乘法序列连续性

设λ，μ是两个序列空间并有符号弱滑脊性，（λ，μ）是变换λ进入μ的无穷矩阵算子所成的无穷矩阵代数，本文研究了这类代数的强，Mackey、弱乘法序列连续性问题。     

关于无穷矩阵算子代数∑(λ,μ)的乘法连续性问题

本文对序列空间λ,μ之间的无穷矩阵算子代数∑（λ,μ）引入了16种自然的拓扑,并就这些拓补给出乘法连续性的刻划;同时,结合对∑（ω,Φ）乘法连续性的细致讨论,研究了∑（λ,μ）的乘法恒不连续的拓扑,从而全面推广并发展了[1-3]的工作．     

关于无穷矩阵算子代数∑(λ,μ)的 乘法连续性问题

本文对序列空间λ,μ之间的无穷矩阵算子代数∑（λ,μ）引入了16种自然的拓扑,并就这些拓补给出乘法连续性的刻划;同时,结合对∑（ω,Φ）乘法连续性的细致讨论,研究了∑（λ,μ）的乘法恒不连续的拓扑,从而全面推广并发展了[1-3]的工作．     

Banach空间上一类由算子导出的局部凸拓扑

本文我们研究了由半范簇｛ＰＴ｜Ｔ∈ψ（Ｅ，Ｅ１）｝在Ｅ上导出的局部凸拓扑σＥ（Ｅ１），其中ＰＴ（ｘ）＝Ｔｘ的范数，ｘ∈Ｅ。首先我们给出了拓扑σＥ（Ｅ１）＝ω和σＥ（Ｅ１）＝Ｅ上的范数的等价条件，接着讨论了在σＥ（Ｅ１）下的紧性与完备性，最后利用空间稠密特征和关于无穷基数幂等的Ｈｅｓｓｅｎｂｅｒｇ定理进一步研究了σＥ（Ｅ１）与Ｅ上的范数的关系，证明了当Ｅ的稠密特征足够大时在ω和Ｅ上的范数间有无穷多个     

拓扑线性空间上一类矩阵变换

对拓扑线性空间之间的一类映射(包括线性算子全体和一类非线性算子)所作矩阵得到一系列基本的矩阵变换定理.     

算子代数上导子空间的拓扑自反性

It is proved that the spaces of derivations on some operator algebras are topologically reflexive in the weak operator topology.     

缺项算子矩阵的二阶代数(Ⅰ)

对于任意给定的二阶多项式ｐ（ｔ）;本文获得希尔伯特空间上形如（?）的缺项算子矩阵具有一个补Ｔ使得ｐ（Ｔ）＝０成立的充分必要条件以及使得ｐ（Ｔ）＝０且ｐ（Ｔ）的范数不大于事先给定常数的充分必要条件．进而还求出所有可能的二阶代数补,特别地,对有限维情形给出简洁的表示。     

一类算子矩阵特征值的代数指标和代数重数

自伴算子特征值的几何重数与代数重数相等,但对于非自伴算子不一定成立,这主要是特征值的代数指标起着决定性的作用.讨论了一类非自伴算子矩阵特征值的几何重数,代数指标与代数重数.     

关于(λ,μ)的乘积定理

本文证明了无穷矩阵算子代数（λ,μ）在左（右）强、Ｋ收敛意义下的乘积定理成立,给出了（λ,μ）在弱收敛意义下乘积定理成立的充要条件。     

Lattice orders on matrix algebras

We construct all the lattice orders (up to isomorphism) on a full matrix algebra over a subfield of the field of real numbers so that it becomes a lattice-ordered algebra. Received June 26, 2001; accepted in final form February 9, 2002.     

A proof of Weinberg's conjecture on lattice-ordered matrix algebras

Let be a subfield of the field of real numbers and let () be the matrix algebra over . It is shown that if is a lattice-ordered algebra over in which the identity matrix 1 is positive, then is isomorphic to the lattice-ordered algebra with the usual lattice order. In particular, Weinberg's conjecture is true.

     

On the scarcity of lattice-ordered matrix algebras II

We correct and complete Weinberg's classification of the lattice-orders of the matrix ring and show that this classification holds for the matrix algebra where is any totally ordered field. In particular, the lattice-order of obtained by stipulating that a matrix is positive precisely when each of its entries is positive is, up to isomorphism, the only lattice-order of with . It is also shown, assuming a certain maximum condition, that is essentially the only lattice-order of the algebra in which the identity element is positive.

     

Weighted infinitesimal unitary bialgebras,pre-Lie,matrix algebras,and polynomial algebras

Motivated by comatrix coalgebras, we introduce the concept of a Newtonian comatrix coalgebra. We construct an infinitesimal unitary bialgebra on matrix algebras, via the construction of a suitable coproduct. As a consequence, a Newtonian comatrix coalgebra is established. Furthermore, an infinitesimal unitary Hopf algebra, under the view of Aguiar, is constructed on matrix algebras. By the close relationship between pre-Lie algebras and infinitesimal unitary bialgebras, we erect a pre-Lie algebra and a new Lie algebra on matrix algebras. Finally, a weighted infinitesimal unitary bialgebra on non-commutative polynomial algebras is also given.     

Degree of matrix relation algebras

We show that a relation algebra and its n-matrix relation algebra have the same degree for all positive integers n. An intermediate result relates the degree of a relation algebra to the degree of a relativization with respect to equivalence elements. Received July 18, 2001; accepted in final form April 24, 2002.