摘要:

In this paper we discuss the structure of some productG=ABof nilpotent subgroupsAandB. In particular we prove that ifGis a minimax soluble group or a finitely generated linear group and if it does not have non-trivial periodic normal subgroups, thenGis metanilpotent.

ISSN:0092-7872    

DOI:10.1080/00927879808826339

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

We give the list of all possible congruences inG(1,4) of degreed≤10 and we explicitely construct most of them.

ISSN:0092-7872    

DOI:10.1080/00927879808826340

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

We introduce the notion of Pfaffian linkage in codimension three and give sufficient conditions for the linked variety to be smooth. As a result, we are able to construct smooth congruences of lines in P4whose existence was an open problem.

ISSN:0092-7872    

DOI:10.1080/00927879808826341

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

In this paper we develop a very basic method to classify (J, σ)-irreducible monoids of typeA4. As a typical example, we list all the types for the monoids corresponding to the strongly dominant weights. This example also shows that there is no general theorem to determine the cross-section lattices for reductive monoids according to their Dynkin diagrams as Putcha and Renner’s recipe forJ-irreducible monoids.

ISSN:0092-7872    

DOI:10.1080/00927879808826342

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

We study the varieties that parametrize trigonal curves with assigned Weierstrass points; we prove that they are irreducible and compute their dimensions. To do so, we stratify the moduli space of all trigonal curves with given Maroni invariant.

ISSN:0092-7872    

DOI:10.1080/00927879808826343

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826344

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

LetKbe a field, charK≠2, and letVkbe ak-dimensional vector space overKequipped with a nondegenerate symmetric bilinear form. DenoteCkthe Clifford algebra ofVk. We study the polynomial identities for the pair (Ck,Vk). A basis of the identities for this pair is found. It is proved that they are consequences of the single identity [x2,y] = 0 whenk= ∝ It is shown that whenk< ∝ the identities for (Ck,Vk) follow from[x2,y]=0 andWk+1= 0 whereWk+1is an analog of the standard polynomialStk+1DenoteM2(K) the matrix algebra of order two overK, and letsl2(K) be the Lie algebra of all traceless 2 × 2 matrices overK. As an application, new proof of the fact that the identity [x2,y] = 0 is a basis of the weak Lie identities for the pair (M2(K),sl2(K) is given.

ISSN:0092-7872    

DOI:10.1080/00927879808826345

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879808826346

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

An associative ring R with identity is said to satisfy related comparability provided that for any idempotents e, f ∈ R with e = 1+ ab and f = 1+ba for some a, b ∈R, there exists a central idempotent u ∈R such that ueR is isomorphic to a direct summand of ufR and (1-u)fR is isomorphic to a direct summand of (1 - u)eR In this paper, we investigate the power-cancellation properties of modules over exchange rings satisfying related comparability.

ISSN:0092-7872    

DOI:10.1080/00927879808826347

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor

摘要:

Let R be a commutative ring with identity and letMbe anR-module. We examine the situation where for each prime ideal ρof R the set of all ρ-prime submodules ofMis finite. In caseRis Noetherian andMis finitely generated, we prove that this condition is equivalent to there being a positive integernsuch that for every prime ideal ρ ofR, the number of ρ-prime submodules ofMis less than or equal ton. We further show that in this case, there is at most one ρ-prime submodule for all but finitely many prime ideals ρ ofR.

ISSN:0092-7872    

DOI:10.1080/00927879808826348

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1998

数据来源: Taylor