摘要:

This work, jointly with [9], completes the structure theory and classification of the JordanH*- triple systems. The problem of describing the JordanH*-triple systems is reduced in [5] to that of describing the topologically simple ones. Ruling out the finite-dimensional case, we have that any of theseH*-triples has an underlying triple system structure of quadratic type (and these can be fully described), or it is theH*-triple system associated to the odd part of a topologically simple Z2-graded JordanH*-algebra, whose classification is given in [13].

ISSN:0092-7872    

DOI:10.1080/00927870008827114

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

For the Hermitian curveHdefined over the finite field, we give a complete classification of Galois coverings ofHof prime degree. The corresponding quotient curves turn out to be special cases of wider families of curves-covered byHarising from subgroups of the special linear groupSL(2,Fq) or from subgroups in the normaliser of the Singer group of the projective unitary group. Since curves-covered byHare maximal over, our results provide some classification and existence theorems for maximal curves having large genus, as well as several values for the spectrum of the genera of maximal curves. For everyq2, both the upper limit and the second largest genus in the spectrum are known, but the determination of the third largest value is still in progress. A discussion on the “third largest genus problem“ including some new results and a detailed account of current work is given.

ISSN:0092-7872    

DOI:10.1080/00927870008827115

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

For a towerof algebraic function fields Fi/Fqdefine λ:=limi→∞N(Fi)/g(Fi) whereN(Fi) is the number of rational places and g(Fi) is the genus ofFi/FqThe purpose of this note is to calculate λ for a class of towers which was studied in [1], [2] and [3].

ISSN:0092-7872    

DOI:10.1080/00927870008827116

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

Must the coefficients of the minimum polynomial of a matrix over a domain lie in that domain? This question leads to the notion of a weakly integrally closed domain, over which the answer is ’yes’ for 3-by-3 matrices. It is shown that certain subalgebras ofk[t] are weakly integrally closed, as are rings consisting of quadratic algebraic numbers.

ISSN:0092-7872    

DOI:10.1080/00927870008827117

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

LetRbe a Dedekind domain with quotient fieldKand let[Rbar]be the integral closure ofRin an algebraic closure ofK

ISSN:0092-7872    

DOI:10.1080/00927870008827118

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

This paper answers the open question 12.73 in “Unsolved Problems in Group Theory, The Kourovka Notebook, 1995“. This paper give an example to show that this question has a negative solution, and give a condition under which the conclusion of the question is correct.

ISSN:0092-7872    

DOI:10.1080/00927870008827119

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

We study locally finite algebras and twisted group algebras with units satisfying a group identity. As a preliminary result, we obtain a necessary condition for twisted group algebras to satisfy a generalized polynomial identity.

ISSN:0092-7872    

DOI:10.1080/00927870008827120

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

The concept of the orthogonality is important in the study of lattice-ordered groups. The purpose of this paper is to investigate a generalization of this concept to directed groups. The idea of anAO-group is introduced here. Some results are obtained concerning convex directed subgroups and Archimedean extensions ofAO-groups. InterpolationAO-groups are also described.

ISSN:0092-7872    

DOI:10.1080/00927870008827121

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

LetRbe a 2-torsion free semiprime ring with extended centroidC. For a derivation δ ofRdenote byCδthe constants of δ onC. We prove that ifis a derivation ofRC, where ø(X) ϵC4δ[X2], then ø(δ) = 0. As an immediate consequence, we present a short proof of Ye and Luh’s theorem for arbitrary 2-torsion free semiprime rings.

ISSN:0092-7872    

DOI:10.1080/00927870008827122

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor

摘要:

It is well known that the symmetric groupSntogether with one idempotent of rankn- 1 on a finiten-element setNserves as a set of generators for the semigroupTnof all the total transformations onN. It is also well known that the singular part SingnofTncan be generated by a set of idempotents of rankn- 1. The purpose of this paper is to begin an investigation of the way in which Singnand its subsemigroups can be generated by the conjugates of a subset of elements ofTnby a subgroup ofSn. We look for the smallest subset of elements ofTnthat will serve and, correspondingly, for a characterization of those subgroups ofSnthat will serve. Using some techniques from graph theory we prove our main result:the conjugates of a single transformation of rankn- 1 underGsuffice to generate Singnif and only ifGis what we define to be a 2-block transitive subgroup ofSn.

ISSN:0092-7872    

DOI:10.1080/00927870008827123

出版商:Gordon and Breach Science Publishers Ltd.    

年代:2000

数据来源: Taylor