摘要:

The aim of this paper is to prove criteria of polynomial growth and domestic representation type of schurian vector space categories. A list of all infinitely sincere schurian vector space categories of polynomial growth is obtained.

ISSN:0092-7872    

DOI:10.1080/00927870008827140

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927870008827141

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

Fuchs and Rangaswamy [8] proved that a smooth ascending unionG= U α<λGα of pure B2-subgroups is a B2-group provided either λ = ωoor λ = ω1,/G/ = N1and all the subgroupsGαare decent inG. In this paper, we extend this result to arbitrary cardinal numbers λ under suitable hypotheses on the factor-groupsGα+1/Gα.

ISSN:0092-7872    

DOI:10.1080/00927870008827142

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927870008827143

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927870008827144

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

For a class of generalized Weyl algebras which includes the Weyl algebras Ana criterion is given as to when the category of indecomposable weight and generalized weight modules with supports from a fixed orbit is tame. In tame cases indecomposable modules are described.

ISSN:0092-7872    

DOI:10.1080/00927870008827145

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

Quantum coalgebras are defined and studied. A theory of asso­ciated invariants of 1-1 tangles, knots and links is developed. The notion of quantum coalgebra is more general than dual of quantum algebra. Examples of quantum algebras include quasitriangular Hopf algebras and examples of quantum coalgebras include coquasi triangu­lar Hopf algebras.

ISSN:0092-7872    

DOI:10.1080/00927870008827146

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

The class semigroup of a commutative integral domainRis the semi­groupS(R) of the isomorphism classes of the nonzero ideals ofRwith operation induced by multiplication. We consider Prufer domains of finite character, i.e. Prüfer domains in which every nonzero ideal is contained but in a finite number of maximal ideals. In [1] it is proved that, ifRis such a Prüfer domain, then the semigroupS(Ris a Clifford semigroup, namely it is the disjoint union of the subgroups associated to each idempotent element. In [2] we gave a description of a generating set for the A-semilattice of the idempotent elements ofS(R). In this paper we consider the constituent groups of the class semigroup. We prove that the groups associated to idempotent elements ofS(R) are extensions of class groups of overrings of (R) by means of direct products of archimedean groups of localizations of(R) at idempotent prime ideals.

ISSN:0092-7872    

DOI:10.1080/00927870008827147

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

Generalizing a property of regular resp. finite semigroups a semigroup S is called E-(0-) inversive if for every a ∈S4(a ≠ 0) there exists x ∈Ssuch that ax (≠ 0) is an idempotent. Several characterizations are given allowing to identify the (completely, resp. eventually) regular semigroups in this class. The case that for every a ∈S4(≠ 0) there exist x,y ∈Ssuch that ax = ya(≠ 0) is an idempotent, is dealt with also. Ideal extensions of E- (0-)inversive semigroups are studied discribing in particular retract extensions of completely simple semigroups. The structure of E- (0-)inversive semigroups satisfying different cancellativity conditions is elucidated. 1991 AMS classification number: 20M10.

ISSN:0092-7872    

DOI:10.1080/00927870008827148

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

It is well known from the results of L, A. Nazarova and A. G. Zavadskij [18], [19], see also [25, Chapter 15], that a poset J with one maximal element is of tame prinjective type and of polynomial growth if and only ifJdoes not contain neither any of the Nazarova's hypercritical posets (1,1,1,1,1)*, (1,1,1,2)*,(2,2,3)*, (1,3,4)*,(W,5)*,(1,2,6)*nor the Nazarova-Zavadskij poset (NZ)*(see Table 1 below). In the present paper we extend this result to a class of posets with two maximal elements. We show that Ã-free poset with two maximal elements is of tame representation type and of polynomial growth if and only if the Tits quadratic form qs→ Z (see (1.7) below) associated withJis weakly non-negative andJdoes not contain any of the six posets listed in Table 1 as a peak subposet.

ISSN:0092-7872    

DOI:10.1080/00927870008827149

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor