摘要:

LetAbe a C-algebra with 1. Let ξ=s λ1e1+ … +λnenεAwhere each λiC and e1,… enare orthogonal idempotents inA. We give conditions onAto guarantee that a certain function of ξ is bounded in terms of the λi's. Examples of such algebra are the complex group ringC[G] and the ringMm(C[G]) of matrices overC[G], for arbitrary groupsG. Thus this paper generalizes the result of [PP]: onC[G] (with out usingC*-algebra theory), and that of [LP] onMm(C[G]) (without assuming thatGis finite.

ISSN:0092-7872    

DOI:10.1080/00927879308824683

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

摘要:

We give necessary and sufficient conditions for a ring graded by a hypercentral group to be simple.

ISSN:0092-7872    

DOI:10.1080/00927879308824684

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

摘要:

A ringRis called left (right) SF-ring if all simple left (right)R-modules are flat. It is proved thatRis Von Neumann regular ifRis a right SF-ring whoe maximal essential right ideals are ideals. This gives the positive answer to a qestion proposed by R. Yue Chi MIng in 1985, and a counterexample is given to settle the follwoing question in the negative: IfRis an ERT ring which is one-sided V-ring, isRa left and right V-ring? Some other conditions are given for a SF-ring to be regular.

ISSN:0092-7872    

DOI:10.1080/00927879308824685

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

摘要:

We construct examples of infinitely generated almost *-moduels, i.e. of infinitely generated small modules satisfying the Colpi's conditionC(K) for allR< N0. We also prove that the examples are shrinkable (in the sense of Facchini and Salce). Hence, they do not satisfyC(N0),and the are not*-modules. This implies that the possible solution of the open problem whether each *-module is finitely generated depends substantially on the validity ofC(R) for infinite cardinalsR

ISSN:0092-7872    

DOI:10.1080/00927879308824686

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

摘要:

In the present paper we consider φ-representations of algebras. (The concept of a φ-representation is denfined in [7] more generaly.) we characterize such representations in terms of congruence relations (see Theorems 1 and 2). The main result of our paper is a unique factorization theorem (cf. Theorem 3). This result implies some classical theorems on direct and subdirect products.

ISSN:0092-7872    

DOI:10.1080/00927879308824687

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879308824688

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879308824689

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879308824690

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

摘要:

In this paper we give a complete description of maximal modular inner ideals of Jordan algebras by determining primitizers of primitive Jordan algebras, as a consequence we answer the question of Hogben and McCrimmon about maximality of such objects.

ISSN:0092-7872    

DOI:10.1080/00927879308824691

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor

摘要:

In this paper we present and prove a simple but non-obvious topological fact. This fact is so simple and funny that can be included in a collection of puzzles or suffested as a problem for a school mathematical tournament. The aim of this article is to present a method by which this fact, in spite of its unserious character. can be applied to produce new non-trivial group-theoretic results.

ISSN:0092-7872    

DOI:10.1080/00927879308824692

出版商:Marcel Dekker, Inc.    

年代:1993

数据来源: Taylor