CHAIN CONDITIONS FOR C＊-ALGEBRAS COMING FROM HILBERT C＊-MODULES

In this paper we define and study chain conditions for Hilbert C＊-modules through their C＊-algebras of compact operators and discuss their perseverance under Morita equivalence and tensor products. We show that these chain conditions are passed from the C＊-algebra to its Hilbert module under certain conditions. We also study chain conditions for Hilbert modules coming from inclusion of C＊-algebra with a faithful conditional expectation.

C^＊-Structure of Quantum Double for Finite Hopf C^＊-Algebra

Let H be a finite Hopf C^＊ -algebra and H′be its dual Hopf algebra. Drinfeld＇s quantum double D（H） of H is a Hopf^＊-algebra. There is a faithful positive linear functional θ on D（H）. Through the associated Gelfand-Naimark-Segal （GNS） representation, D（H） has a faithful^＊ -representation so that it becomes a Hopf C^＊ -algebra. The canonical embedding map of H into D（H） is isometric.

ISOMORPHISMS AND DERIVATIONS IN C*-ALGEBRAS

In this article, we prove the Hyers-Ulam-Rassias stability of the following Cauchy-Jensen functional inequality：‖f （x） ＋ f （y） ＋ 2f （z） ＋ 2f （w）‖ ≤‖ 2f x ＋ y2 ＋ z ＋ w ‖（0.1）This is applied to investigate isomorphisms between C＊-algebras, Lie C＊-algebras and JC＊-algebras, and derivations on C＊-algebras, Lie C＊-algebras and JC＊-algebras, associated with the Cauchy-Jensen functional equation 2f （x ＋ y/2 ＋ z ＋ w） = f（x） ＋ f（y） ＋ 2f（z） ＋ 2f（w）.

Certain classes of C＊-algebras preserved by tracial approximation

We show that the following classes of C＊-algebras in the classes t are inherited by simple unital C＊-algebras in the classes TAft ： （1） simple unital purely infinite C＊-algebras, （2） unital isometrically rich C＊-algebras, （3） unital Riesz interpolation C＊-algebras.

Hopf ＊-algebra structures on H（1, q）

We study the Hopf ＊-algebra structures on the Hopf algebra H（1, q） over C. It is shown that H（1, q） is a Hopf ＊-algebra if and only if ｜q｜ = 1 or q is a real number. Then the Hopf ＊-algebra structures on H（1, q） are classified up to the equivalence of Hopf ＊-algebra structures.

On Representations Associated with Completely n-Positive Linear Maps on Pro-C^＊-Algebras

It is shown that an n × n matrix of continuous linear maps from a pro-C^＊-algebra A to L（H）, which verifies the condition of complete positivity, is of the form [V^＊TijФ（·）V]^n i,where Ф is a representation of A on a Hilbert space K, V is a bounded linear operator from H to K, and j=1,[Tij]^n i,j=1 is a positive element in the C^＊-algebra of all n×n matrices over the commutant of Ф（A） in L（K）. This generalizes a result of C. Y.Suen in Proc. Amer. Math. Soc., 112（3）, 1991, 709-712. Also, a covariant version of this construction is given.

一种基于对象关系模型的时空查询代数stor-algebra

通过对目前已有的时空数据库技术在易于实现的时空查询代数方面进行的深入研究,提出了一种基于对象关系的时空查询代数stor-algebra,从数据结构和代数操作两方面进行了详细描述.stor-algebra兼容关系代数,并可在对象关系数据库管理系统上实现,可作为时空查询处理系统的代数基础.

Diagonal Invariant Ideals of Topologically Graded C~*-algebras

We study diagonal invariant ideals of topologically graded C*-algebras over discrete groups. Since all Toeplitz algebras defined on discrete groups are topologically graded, the results in this paper have improved the first author's previous works on this topic.

Min-Algebra上矩阵的μ值

利用矩阵理论研究了一类特殊的半环-(Rmin,,,∞)上的矩阵的秩、列秩和极大列秩之间的关系,得到了对于min-algebra上任意m×n矩阵,使这3类秩相等的最大整数,即矩阵的μ值的所有情形,扩展了已有的相关结论.

Gelfand-Naimark Theorem of Commutative Hopf C^＊ -Algebras

Let A be a commutative C^＊ -algebra. By the Gelfand-Naimark theorem, there exists a locally compact space G such that A is isomorphic to Co（G）, the C^＊-algebra of all complex continuous functions on G vanishing at infinity. The result is generalized to the ease of Hopf C^＊-algebra, where G is altered by a locally compact group. Using the isomorphic representation, the counit ε and the antipode S of a commutative Hopf C^＊-algebra are proposed.

Von Neumann Regularity and Quadratic Conorms in JB^＊-triples and C^＊-algebras

We revise the notion of von Neumann regularity in JB^＊-triples by finding a new characterisation in terms of the range of the quadratic operator Q（a）. We introduce the quadratic conorm of an element a in a JB^＊-triple as the minimum reduced modulus of the mapping Q（a）. It is shown that the quadratic conorm of a coincides with the infimum of the squares of the points in the triple spectrum of a. It is established that a contractive bijection between JBW^＊-triples is a triple isomorphism if, and only if, it preserves quadratic conorms. The continuity of the quadratic conorm and the generalized inverse are discussed. Some applications to C^＊-algebras and von Neumann algebras are also studied.

K-theory of Continuous Deformations of C＊-algebras

We study K-theory of continuous deformations of C＊-algebras to obtain that their K-theory is the same as that of the fiber at zero. We also consider continuous or discontinuous deformations of Cuntz and Toeplitz algebras.

Partial Isometries and an Invariant of C＊-algebras

In this paper, we will discuss some properties of biprojection-commutative elements which are relevant to the classification of certain infinite C＊-algebras,, and define an important invariant s（A） of C＊-algebra A as well as give some basic properties with regard to s（A）. Moreover we prove that the invariant s（A） has continuity.

On a geometric realization of C^＊-algebras

Further to the functional representations of C^＊-algebras proposed by R. Cirelli and A. Manik, we consider the uniform Kahler bundle （UKB） description of some C^＊-algebraic subjects. In particular, we obtain a one-to- one correspondence between closed ideals of a C^＊-algebra A and full uniform Kahler subbundles over open subsets of the base space of the UKB associated with A. In addition, we present a geometric description of the pure state space of hereditary C^＊-subalgebras and show that if B is a hereditary C^＊-subalgebra of A, the UKB of B is a kind of Kahler subbundle of the UKB of A. As a simple example, we consider hereditary C^＊-subalgebras of the C^＊-algebra of compact operators on a Hilbert space. Finally, we remark that each hereditary C^＊- subalgebra of A also can be naturally characterized as a uniform holomorphic Hilbert bundle.

The N-Isometric Isomorphisms in Linear N-Normed C^＊-Algebras

We prove the Hyers-Ulam stability of linear N-isometries in linear N-normed Banach mod- ules over a unital C^＊-algebra. The main purpose of this paper is to investigate N-isometric C^＊-algebra isomorphisms between linear N-normed C^＊-algebras, N-isometric Poisson C^＊-algebra isomorphisms between linear N-normed Poisson C^＊-algebras, N-isometric Lie C^＊-algebra isomorphisms between linear N-normed Lie C^＊-algebras, N-isometric Poisson JC^＊-algebra isomorphisms between linear N-normed Poisson JC^＊-algebras, and N-isometric Lie JC^＊-algebra isomorphisms between linear N-normed Lie JC^＊-algebras. Moreover, we prove the Hyers- Ulam stability of t：heir N-isometric homomorphisms.

Near-algebra和Banach代数上的特征值和不动点定理(英文)

在near-algebra和Banach代数中引入(p,q)-可加自映象f和正则可逆元的概念,得到如下的结果:在一定条件下,对于定义在near-algebra或Banach代数X中(p,q)-可加自映象f,X中的任意正则可逆元都具有公共的特征值λ=2q/(1+q),p=q≠-1.其特例就是当λ=2q/(1+q)=1时,X中的任意正则可逆元都是(p,q)-可加自映象f的不动点.

Fuzzy BCC-algebra and Fuzzy BCC-ideal

引入ＦＵＺＺＹＢＣＣ－代数、ＦＵＺＺＹＢＣＣ－理想的概念，讨论了它们的性质，从而将ＦＵＺＺＹＢＣＫ－代数的有关结果推广到ＢＣＣ－代数上．

AF-Embedding of Crossed Products of Certain Graph C＊-algebras by Quasi-free Actions （II）

Let E be a row-finite directed graph, let G be a locally compact abelian group with dual group G = F, let w be a labeling map from E＊ to F, and let （C＊（E）, G,a^w） be the C＊-dynamical system defined by w. Some mappings concerning the AF-embedding construction of C＊ （E） X（aw） G are studied in more detail. Several necessary conditions of AF-embedding and some properties of almost proper labeling map are obtained. Moreover it is proved that if E is constructed by attaching some l-loops to a directed graph T consisting of some rooted directed trees and G is compact, then oJ is k almost proper, that is a sufficient condition for AF-embedding, if and only if ∑j^Kk=1^wγ j ≠fi 1r for any loop γi, γ2 …γk attached to one path in T

A Note on the Monotone Product of Nuclear C^＊-Algebras

Given two nuclear C^＊-algebras A1 and A2 with states φ1 and φ2, we show that the monotone product C^＊-algebra A1 △→ A2 is still nuclear. Furthermore, if both the states φ1 and φ2 are faithful, then the monotone product ,A1 △→ A2 is nuclear if and only if the C^＊-algebras ,A1 and A2 both are nuclear.

Isometric Isomorphisms in Proper CQ＊-algebras

In this paper, we prove the Hyers-Ulam-Rassias stability of isometric homomorphisms in proper CQ＊-algebras for the following Cauchy-Jensen additive mapping： 2f[（x1＋x2）/2＋y]=f（x1）＋f（x2）＋2f（y） The concept of Hyers-Ulam-Rassias stability originated from the Th.M. Rassias＇ stability theorem that appeared in the paper： On the stability of the linear mapping in Banach spaces, Proc. Amer. Math. Soc., 72 （1978）, 297-300. This is applied to investigate isometric isomorphisms between proper CQ＊-algebras.