摘要:

Let A be a representation-finite simply connected algebra, and TAbe an arbitrary tilting module (in the sense of Happei and Ringel). We show that B = End TAsatisfies the separation condition of Bautista, Larrion and Salmeron. This implies that B is also simply connected.

ISSN:0092-7872    

DOI:10.1080/00927879408825091

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879408825092

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879408825093

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

摘要:

For a maximal eubgroup M of a finite group G, a 8-pair is any pair of subgroups (C,D) of G such that (i) D▹G, D≤C, (ii) <M, C> - G, <M, D> - M and (iii) C/D has no proper normal subgroup of G/D. A partial order may be defined on the family of 8-pairs. Let △(M) - {(C,D)|(C,D) is a maximal 8-pair and CM - G}. The purpose of this note is to prove: (1) A group G is solvable if and only if, for each maximal subgroup M of G, △(M) contains a 8-pair (C,D) such that C/D ie nilpctent. (2) If a group G is S4-free, then G ia eupersolvable if and only if, for each maximal subgroup M of G, △(M) contains a 8-pair (C,D) auch that C/D is cyclic

ISSN:0092-7872    

DOI:10.1080/00927879408825094

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879408825095

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

摘要:

In this paper we study coalgebras, that is, vector spaces A with a linearmap A→A⊗A. To every coalgebra A one can associate an algebra on its dual A*such that A becomes a bimodule for A*. We exploit this construction to define the concept of a variety of coalgebras unifying under a general framework the known examples of associative and Lie coalgebras: A is a coalgebra of the variety θ if A*is an algebra in θ. On the other hand we study structural properties of coalgebras by translating them into the language of algebras. In particular we prove the analogue of the Fundamental Theorem on associative coalgebras Q]: alternative and Jordan coalgebras are locally finite

ISSN:0092-7872    

DOI:10.1080/00927879408825096

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879408825097

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

摘要:

An associative ring R with identity is semiperfect if and only if every element of R is a sum of a unit and an idempotent, and R contains no infinite set of orthogonal idempotents. A ring which contains no infinite set of orthogonal idempotents is an exchange ring if and only if every element is a sum of a unit and an idempo-tent

ISSN:0092-7872    

DOI:10.1080/00927879408825098

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

摘要:

In this paper we give a deterministic construction for a Normal basis of Kf over K, where K' is an abelian extension of finite degree n over some commutative, infinite field K. No particular property for K is needed.We use polynomials already defined in [2], [5, chapter 5], In these papers the field K was finite. These polynomials were used in order to construct SDMC codes [5,chapter 6], to determine bivariate codes [2],[3], or to obtain the best possible principal nilpotent codes [6], Our construction is deduced from new properties of these polynomials

ISSN:0092-7872    

DOI:10.1080/00927879408825099

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879408825100

出版商:Marcel Dekker, Inc.    

年代:1994

数据来源: Taylor