ISSN:0092-7872    

DOI:10.1080/00927879808826242

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

LetSbe a monoid. It is shown that all strongly flat leftS-acts are regular if and only if all leftS-acts having the property (E) are regular if and only ifSis a left PP monoid and satisfies (FP2).This result answers a question in Kilp and Knauer [5].

ISSN:0092-7872    

DOI:10.1080/00927879808826243

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826244

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826245

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

LetFbe an algebra which is free in a class of algebras. In this paper we consider the following problem:If an endomorphism ψ ofFpreserves the orbit (AutF)(ω) of a nontrivial element ω ∈F, does this imply that ψ is an automorphism? We give positive solutions of this problem whenFis generated by two elements and is the free Lie algebra, free metabelian Lie algebra or free metabelian associative algebra, and ω is a certain kind of element.

ISSN:0092-7872    

DOI:10.1080/00927879808826246

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826247

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

A subgroupHof a finite groupGis said to be c-normal inGif there exists a normal subgroupNofGsuch thatHN=GandH∩N≤HG=coreG(H).In this paper we shall investigate the influence of c-normality of some subgroups on the strcture of finite groups further, and obtain some results on some kinds of weaker conditions.

ISSN:0092-7872    

DOI:10.1080/00927879808826248

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826249

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

A sharp lower bound for the rank of the natural multiplication mapH0(F) ⊗H0(G) →H0(F⊗G) is givenFandGbeing vector bundles generically generated by their global sections on an integral projective variety.Some Clifford-type inequalities in the context of the Brill-Noether theory of vector bundles on a curve are proved and their sharpness is studied.

ISSN:0092-7872    

DOI:10.1080/00927879808826250

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

For an excellent ringAwhose real spectrum satisfies some connectedness condition, we give a sensible notion of real analytic component for a Zariski closed subset of SpecrA(such a closed subset will also be called a locally Nash set).Indeed we show that the locally Nash sets are the closed subsets of a noetherian topology on an abstract new spaceGwhich we introduce.This generalizes the geometric notion of global real analytic component whenAis the ring of global Nash functions on an affine Nash manifold.

ISSN:0092-7872    

DOI:10.1080/00927879808826251

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor