因子von Neumann代数中套子代数上的Jordan同构

研究了因子yon Neumann代数中套子代数上的Jordan同构,证明了套子代数algMβ和algMγ之间的每一个Jordan同构φ:要么是同构;要么是反同构.     

因子von Neumann代数中套子代数上Jordan同构的刻画

本文研究了套子代数上由零积确定的子集中保Jordan积的线性映射与同构和反同构的关系.证明了若对任意的A,B∈algMβ且AB=0,有Φ(A■B)=Φ(A)■Φ(B)成立,则Φ是同构或反同构.其中,algMβ,algMγ是因子von Neumann代数M中的两个非平凡套子代数,Φ:algMβ→algMγ是一个保单位线性双射.     

Von Neumann代数套子代数上保因子交换性的线性映射

对因子von Neumann代数的套子代数上的保单位线性映射Φ:AlgMα→AlgMβ满足AB=ξBA(?)Φ(A)Φ(B)=ξΦ(B)Φ(A)进行了刻画,其中A,B∈AlgMα,ξ∈F,即证明了因子von Neumann代数的套子代数间每个保单位的弱连续线性满射它双边保因子交换性,则映射Φ或者是同构或者是反同构.     

Von Neumann代数中的套子代数

本文主要讨论因子Ｖｏｎ Ｎｅｕｍａｎｎ代数中套子代数上的线性满等距和自伴导子．证明了因子Ｖｏｎ Ｎｅｕｍａｎｎ代数中套子代数上的每个线性满等距是同构乘酉算子或者是反同构乘酉算子；给出了其上自伴导子是内导子的条件并得到有限因子 Ｖｏｎ Ｎｅｕｍａｎｎ代数中套子代数上的每个自伴导子都是内导子．     

von Neumann 代数上保持混合Jordan三重积的非线性映射

本文证明了在没有中心交换投影的von Neumann代数上的一个双映射$\Phi$如果保持混合Jordan三重积, 则$\Phi(I)\Phi$是一个线性*-同构和一个共轭线性*-同构的和, 其中$\Phi(I)$是中心自伴元素且$\Phi(I)^{2}=I$. 同时给出了因子von Neumann 代数上保持混合Jordan三重积映射的结构.     

因子Von Neumann代数中套子代数上的局部3-上循环

证明了因子von Neumann代数中的套子代数到其单位对偶双模内的每个弱连续的局部3-上循环都是3-上循环.     

von Neumann代数中套子代数的摄动

本文主要讨论ｖｏｎ　Ｎｅｕｍａｎｎ代数中套子代数的摄动．给出了因子ｖｏｎ　Ｎｅｕｍａｎｎ代数中套相似的一个充分条件．证明了任何因子ｖｏｎ　Ｎｅｕｍａｎｎ代数中相邻的套子代数经由一个邻近于单位元的可逆算子是相似的．     

算子代数的性质∏_σ和张量积

本文引入算子代数的性质Ⅱ_σ这一概念,证明了任一von Neumann代数中的套子代数和有限宽度CSL子代数都具有性质Ⅱ_σ.最后得到张量积公式alg_ML_1■alg_NL_2= alg_(M■N)(L_1L_2)成立,这里L_1和L_2分别是von Neumann代数M和N中的有限宽度CSL.     

算子代数的超滤积

研究了C^*代数和von Neumann代数的超滤积的一些基本问题，包括和C^*代数K理论的关系.特别地, 证明了在一定的条件下, C^*代数超滤积的K群同构于相应C^*代数K群的超滤积, 还证明了II₁型因子的超滤积是素的, 也就是说, 不同构于任意非平凡的张量积.     

交换半环上三角矩阵代数的Jordan同构

探讨交换半环上的上三角矩阵代数的Jordan同构.证明如果R是一个交换半环且R中仅有幂等元0与1,那么从R上的上三角矩阵代数Tn(R)到R上的任意代数的每一个Jordan同构要么是一个同构要么是一个反同构.     

Linear maps preserving zero products on nest subalgebras of von Neumann algebras

In this paper, it is proved that every surjective linear map preserving identity and zero products in both directions between two nest subalgebras with non-trivial nests of any factor von Neumann algebra is an isomorphism; and that every surjective weakly continuous linear map preserving identity and zero Jordan products in both directions between two nest subalgebras with non-trivial nests of any factor von Neumann algebra is either an isomorphism or an anti-isomorphism.     

Property ∏σ and tensor products of operator algebras

In this paper, we introduce Property ∏σ of operator algebras and prove that nest subalgebras and the finite-width CSL subalgebras of arbitrary von Neumann algebras have Property ∏σ.Finally, we show that the tensor product formula alg ML1-(×)algNL2 = algM-(×)N(L1 (×) L2) holds for any two finite-width CSLs L1 and L2 in arbitrary von Neumann algebras M and N, respectively.     

Von Neumann代数中套子代数上的导子(Ⅱ)

本文主要研究因子ＶｏｎＮｅｕｍａｎｎ代数中套子代数上的导子。证明了由因子ＶｏｎＮｅｕｍａａｎ代数中套子代数到紧算子的任何导子都是内导子。     

Vertex-Compressed Subalgebras of a Graph von Neumann Algebra

In Cho (Acta Appl. Math. 95:95–134, 2007 and Complex Anal. Oper. Theory 1:367–398, 2007), we introduced Graph von Neumann Algebras which are the (groupoid) crossed product algebras of von Neumann algebras and graph groupoids via graph-representations, which are groupoid actions. In Cho (Acta Appl. Math. 95:95–134, 2007), we showed that such crossed product algebras have the amalgamated reduced free probabilistic properties, where the reduction is totally depending on given directed graphs. Moreover, in Cho (Complex Anal. Oper. Theory 1:367–398, 2007), we characterize each amalgamated free blocks of graph von Neumann algebras: we showed that they are characterized by the well-known von Neumann algebras: Classical group crossed product algebras and (operator-valued) matricial algebras. This shows that we can provide a nicer way to investigate such groupoid crossed product algebras, since we only need to concentrate on studying graph groupoids and characterized algebras. How about the compressed subalgebras of them? i.e., how about the inner (cornered) structures of a graph von Neumann algebra? In this paper, we will provides the answer of this question. Consequently, we show that vertex-compressed subalgebras of a graph von Neumann algebra are characterized by other graph von Neumann algebras. This gives the full characterization of the vertex-compressed subalgebras of a graph von Neumann algebra, by other graph von Neumann algebras.     

ORTHOGONAL DECOMPOSITIONS AND IDEMPOTENT CONFIGURATIONS IN SEMISIMPLE ASSOCIATIVE ALGEBRAS

This is an introductory survey on the theories of orthogonal decompositions of associative algebras, balanced systems of idempotents, H-bijections of groups and H _R -isomorphisms of group rings. These new theories have grown up from the investigations of orthogonal decompositions of simple Lie algebras into a sum of Cartan subalgebras carried out by A. I. Kostrikin with collaborators.     

导子的范数估计

本文给出了因子 ｖｏｎ Ｎｅｕｍａｎｎ代数中套子代数上导子的范数估计．利用此结果得到一个距离公式,并证明了因子 ｖｏｎ Ｎｅｕｍａｎｎ代数中的任何套子代数都具有ＡＩＰ（ｒ, ｓ）性质     

Von Neumann Algebras and Hilbert Quantales

When A is a von Neumann algebra, the set of all weakly closed linear subspaces forms a Gelfand quantale, Max_w A. We prove that Max_w A is a von Neumann quantale for all von Neumann algebras A. The natural morphism from Max_w A to the Hilbert quantale on the lattice of weakly closed right ideals of A is, in general, not an isomorphism. However, when A is a von Neumann factor, its restriction to right-sided elements is an isomorphism and this leads to a new characterization of von Neumann factors.