Construction of semisimple category over generalized Yetter-Drinfeld modules

Let H be a commutative, noetherian, semisimple and cosemisimple Hopf algebra with a bijective antipode over a field k. Then the semisimplicity of YD（H） is considered, where YD （H） means the disjoint union of the category of generalized Yetter-Drinfeld modules nYD^H（ α, β） for any α, β E Aut Hopf（H）. First, the fact that YD（H） is closed under Mor is proved. Secondly, based on the properties of finitely generated projective modules and semisimplicity of H, YD（H） satisfies the exact condition. Thus each object in YD（H） can be decomposed into simple ones since H is noetherian and cosemisimple. Finally, it is proved that YD （H） is a sernisimple category.

LOCAL AUTOMORPHISMS OF SEMISIMPLE ALGEBRAS AND GROUP ALGEBRAS

Let F be a field of characteristic not 2, and let A be a finite-dimensional semisimple F -algebra. All local automorphisms of A are characterized when all the degrees of A are larger than 1. If F is further assumed to be an algebraically closed field of characteristic zero, K a finite group, F K the group algebra of K over F , then all local automorphisms of F K are also characterized.

Some Characterizations of Strongly Semisimple Ordered Semigroups

In this paper, the concept of quasi-prime fuzzy left ideals of an ordered semigroup S is introduced. Some characterizations of strongly semisimple ordered semigroups are given by quasi-prime fuzzy left ideals of S. In particular, we prove that S is strongly semisimple if and only if each fuzzy left ideal of S is the intersection of all quasi-prime fuzzy left ideals of S containing it.

On Restricted Lie Superalgebras with Semisimple Elements

In the present paper, we give some sufficient conditions for the commutativity of restricted Lie superalgebras and characterize some properties of restricted Lie superalgebras with semisimple elements.

On S-acts containing no maximal S-subacts

Let S be a semigroup and let A be an S-act. Some necessary and sufficient conditions that S-subacts of A are maximal S-subacts are given. A relation B which is similar to the Green relation in semigroups is defined. By the relation B, it is proved that a non-empty set L of A is a maximal S-subact if and only if A／L is a （maximal） B-class. Finally, the concept of a C-subact is defined, some properties of C-subacts are discussed, and it is proved that A contains no maximal S-subacts if and only if every cyclic S-subact of A is a C-subact. Consequently, the results obtained by Imrich Fabrici that semigroups contain no maximal （left） ideals are the corollary of this paper.

Homological Dimensions and Semisimplicity of Relative Hopf Modules

Let H be a Hopf algebra over a field with bijective antipode, and A a commutative cleft right H-comodule algebra. In this paper, we investigate the ho-mological dimensions and the semisimplicity of the category of relative Hopf modulesAMH.

Semisimplicity of u-Quasi-Hopf Algebra

The notions of u-quasi-Hopf algebras and the quantum dimension dimuM of a representation M by u are introduced.It is shown that a u-quasi-Hopf algebra H is semisimple if and only if there is a finite-dimensional projective H-module P such that dimu P is invertible.

THE BSE PROPERTY FOR SOME VECTOR-VALUED BANACH FUNCTION ALGEBRAS

In this paper,X is a locally compact Hausdorff space and A is a Banach algebra.First,we study some basic features of C0(X,A)related to BSE concept,which are gotten from A.In particular,we prove that if C0(X,A)has the BSE property then A has so.We also establish the converse of this result,whenever X is discrete and A has the BSE-norm property.Furthermore,we prove the same result for the BSE property of type I.Finally,we prove that C0(X,A)has the BSE-norm property if and only if A has so.

Hereditary Radicals and Strongly Semisimple Radicals in Normal Classes of Algebras

Puczylowski established the general theory of radicals of the class of objects called algebras. In this paper, we make use of the method of lattice theory to characterize the general hereditary radicals and general strongly semisimple radicals and investigate some properties of them in normal classes of algebras. This extends some known studies on the theory of radicals of various algebraic strutures.

N-半单代数与蕴涵代数

研究了有限结合代数与各种蕴涵代数的联系,得到了一些有趣的结果:N-半单代数的中心幂等元集G(R)按照“→”或者“*”等运算分别构成与蕴涵代数(F I代数、BCK代-数、BC I代-数、BCC代-数、W a jsberg代数等)等价的代数系统。

环的两个交换性定理

证明了满足下列条件的环是交换环1)设R为半质环,若对R中任意元x,y,存在整数m=m(y)>1,n=n(x,y)>1,使得(xmy)n-yxm∈Z(R)则R为交换环.2)设R为kothe半单环,若对R中任意元x,y,存在整数m=m(y)>1,n=n(x,y)>1,使得(xmy)n-yxm∈Z(R)则R为交换环.

一般代数对象的根与半单类

最近,Puczylowski在用公理系统构造的其中元素称为代数的对象类中建立了一般根论.本文的目的是用格论方法给出这种最具广泛性的代数系统的根与半单类的几种特征刻划.此外,探讨SX是半单类的条件.

代数对象的根与半单类(英文)

最近 ,Puczylowski在由公理系统构建的代数对象类中建立了一般根论 .本文的目的是用格论的方法给出根和半单类的刻划 。

关于J-半单半环的一个新刻画

利用半本原半环给出了J 半单半环的一个新刻画.

P-投射模的刻画

模M称为P-投射模,是指对任意R-模N的任意循环子模Rx,同态f:M→N/Rx能提升为同态g:M→N.给出了P-投射模的一些新刻划,证明了M是P-投射模当且仅当对任何有限生成模K有Ext1R(M,K)=0当且仅当对R的任何左理想I有Ext1R(M,R/I)=0.并利用P-投射性与f-内射性给出了半单环的新刻划,证明了R是半单环当且仅当每个模是P-投射模当且仅当每个模是f-内射模.最后为了进一步揭示P-投射模的子模的性质,引入了P-遗传环的概念,证明了R是P-遗传环当且仅当有限生成模的内射维数不超过1.

半质环的两个交换性定理

证明了满足下列条件的半质环是交换环:1)若对x,y,z∈R,存在整数m=m(x,z)>1,n=n(x,z)>1,使得[(xmy)n-xym,z]∈Z(R)则R为交换环.2)若对x,y,z∈R,存在整数m=m(y,z)>1,n=n(y,z)>1,使得[(xmy)n+xmy,z]∈Z(R)则R为交换环.

限制李三系的可换性

Hodge和Parshall在文[On the representation theory of Lie triple systems,Trans AmerMath Soc,2002,354(11):4359-4391]中指出,若(T,(-)^([p]))是有限维限制李三系且(-)^([p]):T→T是单射,则T是可交换的.但是,这个结论是不正确的.作者证明了它在代数闭域上是成立的,同时,给出了限制李三系可交换的一些条件,并刻画了限制李三系的p-映射和半单元的一些性质.

完全幂等环

首先得出整完全幂等环是域的结论 ,其次给出有单位元的完全幂等环的两个刻划 ,即有单位的完全幂等环是L 半单的 ,B 半单的 ,最后给出了一类有限完全幂等环的结构 .

奇异模刻划的环

用奇异模给出半单环、正则环的若干刻划 。

群的根性的一般理论

该文列举了任意群的根性的定义,并给出了任意群的根性的几个例子,同时还研究了群的根性的性质.