ISSN:0092-7872    

DOI:10.1080/00927879808826283

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

We give in this note some new bounds onpc(G) in terms of σcfor several classes of finite groups, in particular, we prove that ρc≤4σc(G) for any finite solvable groupG, which improves some known results. We also pose some related open problems.

ISSN:0092-7872    

DOI:10.1080/00927879808826284

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

LetRbe a commutative ring andA↦Mm×n. The spanning rank ofAis the smallest positive integersfor whichA=PQ(m×ss×n) The spanning rank of the zero matrix is set equal to zero. IfRis a field, then the spanning rank ofAis just the classical rank ofA. In the first section of this paper, various theorems and examples are given which indicate how much of the classical theory of rank is still valid for spanning rank over a commutative ring. IfA=PQ(n×ss×n) is a spanning rank factorization of a square matrix andD=QP, thenDis called a spanning rank partner ofA. In the second part of this paper, the null idealsNAandNDofAandDrespectively are compared. For instance, we showNA=NDifs=nandNA=XNDifs<nwheneverRis aPIDandA≠0. This result sometimes (e.g.s<<n) makes the computation ofNAeasy.

ISSN:0092-7872    

DOI:10.1080/00927879808826285

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826286

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826287

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

In this paper we construct a new algebraA★Hof anH- bimodule algebraAby a Hopf algebraHand study some of its properties. The smash product, the Drinfel'd doubleD(H) and the Doi-Takeuchi's algebraB⋈,H, are all special cases ofA★H. Moreover,we find a necessary and sufficient condition forA★Hto be a Hopf algebra and also consider the dual situation

ISSN:0092-7872    

DOI:10.1080/00927879808826288

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

In this work we introduce some classes of modules whose endomorphism rings have some of the properties of the endomorphism rings of vector spaces. Then we apply these notions to obtain new characterizations of semisimple rings and modules.

ISSN:0092-7872    

DOI:10.1080/00927879808826289

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826290

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826291

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826292

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor