摘要:

The notion ofMorita-like equivalencehas been introduced byXu, Shum and Turner-Smith in [13]. Their definition extends the usual Morita equivalence for unital rings to a wider subclass of the class of all(non-unital)associative rings, namely the xst-rings. We study here this class of rings, showing its strong connections to other known classes of rings(s-unital rings, local right identity rings, idempotent rings)and giving a complete description of xst-rings in terms of these known classes. We also show that right xst-rings which are Morita-like equivalent to unital rings come from dense subrings of the endomorphism ring End(AM)of some generator moduleAMover a unital ringA.

ISSN:0092-7872    

DOI:10.1080/00927879908826455

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879908826456

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

摘要:

The natural or “cohomological bases” construction of the determinant of cohomology functor has the problem that a certain diagram that we might want to commute only commutes up to sign, and rinding the value of this sign is a non-trivial problem. The more sophisticated determinant of cohomology functor of Knudson and Mumford has the property that the corresponding diagram commutes, not just up to sign. However, their construction leaves open the question of the sign behavior for the cohomological bases construction

ISSN:0092-7872    

DOI:10.1080/00927879908826457

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879908826458

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

摘要:

The Lie algebra of vector fields Vect(M) of a smooth manifoldMacts by Lie derivatives on the spaceof differential operators of order ≤pthat map fields of densities of weight -λ on fields of densities of weight -μ. In this paper, we determine all the intertwining operators between these modules, when DimM≥ 2.

ISSN:0092-7872    

DOI:10.1080/00927879908826459

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

摘要:

We investigate the submodule structure of α-stratified modules over a Lie algebra of typeG2and obtain a BGG-like criterion for the existence of a non-trivial homomorphism between two generalized Verma modules.

ISSN:0092-7872    

DOI:10.1080/00927879908826460

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

摘要:

We characterize left perfect rings using locally, finitely projective and flat covers, thus answering a question of Xue in the positive.

ISSN:0092-7872    

DOI:10.1080/00927879908826461

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

摘要:

LetRbe a prime ring with extended centroidCUits right Utumi quotient ring andUsits two–sided Utumi quotient ring. We prove the Lie ideal case of Kharchenko’s theorem: Ifis a reduced differential identity for a noncommutative Lie ideal ofR, thenø(Zij) is a GPI for [R, R], As a consequence, we conclude thatRand each noncommutative Lie ideal ofRsatisfy the same differential identities with coefficients inUprovided thatRis not a PI–ring. For the one–sided version of Kharchenko’s theorem we obtain that JR and each large right ideal ofRsatisfy the same differential identities with coefficients inUs.

ISSN:0092-7872    

DOI:10.1080/00927879908826462

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

摘要:

We study the properties of the filtrations which define an adic topology on a ring. As an application, we give a characterization of Zariski rings. Also, we compute filtrations on Dedekind domains and we show that a strongly EP filtration is adic, modulo a finite number of terms.

ISSN:0092-7872    

DOI:10.1080/00927879908826463

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879908826464

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1999

数据来源: Taylor