Relative K0, Annihilators, Fitting Ideals and Stickelberger Phenomena

When G is abelian and l is a prime we show how elements of therelative K-group K₀(Z_l[G], Q_l give rise to annihilator/Fittingideal relations of certain associated Z[G]-modules. Examplesof this phenomenon are ubiquitous. Particularly, we give examplesin which G is the Galois group of an extension of global fieldsand the resulting annihilator/Fitting ideal relation is closelyconnected to Stickelberger's Theorem and to the conjecturesof Coates and Sinnott, and Brumer. Higher Stickelberger idealsare defined in terms of special values of L-functions; whenthese vanish we show how to define fractional ideals, generalisingthe Stickelberger ideals, with similar annihilator properties.The fractional ideal is constructed from the Borel regulatorand the leading term in the Taylor series for the L-function.En route, our methods yield new proofs, in the case of abeliannumber fields, of formulae predicted by Lichtenbaum for theorders of K-groups and étale cohomology groups of ringsof algebraic integers. 2000 Mathematics Subject Classification11G55, 11R34, 11R42, 19F27.     

关于有向图代数中Lie理想的注记

本文加深了Hopenwasser和Paulsen关于有向图代数中Lie理想的一个结果,证明了有向图代数A的一个线性子空间是A的Lie理想当且仅当存在A的一个结合理想Y及A的masa D的一个子代数E,使得(Y)~0■■Y+E,其中(Y)~0是Y中迹为零的所有元的集合．     

Primitive Ideals of Noetherian Generalized Down-Up Algebras

We classify the primitive ideals of noetherian generalized down-up algebras.     

Examples of Infinitely Generated Function Algebras

Examples of non-finitely generated function algebras on planar sets with small maximal ideal spaces are given.     

W－理想与W－软代数

本文给出了Ｗ－理想与Ｗ－软代数的定义，主要结果有（Ⅰ）：（ｄ］，（ｄ＿１］分别是软代数Ｆ的同余理想，ｄ＿１≥ｄ，若（ｄ］是Ｗ－理想，则（ｄ＿１］是Ｗ－理想。（Ⅱ）：分别给出了软代数Ｆ，商软代数Ｆ／θ、软代数的直积Ｆ＝ПＦ＿ｉ是Ｗ－软代数的充分必要条件。     

Quasivarieties of Metric Algebras

We introduce concepts of a continuous family of quasi-identities and of a continuous quasivariety. For continuous quasivarieties, a characterization theorem and an analog of the Birkhoff theorem on subdirect decomposition are proved. Also we point out the way of constructing examples of continuous quasivarieties and furnish the characterization of a relative congruence lattice of systems in the quasivarieties in question. Lastly, we re-prove the Hahn–Banach theorem on extension of a linear functional.     

Deep Matrix Algebras of Finite Type

Deep matrix algebras based on a set over a ring are introduced and studied by McCrimmon when has infinite cardinality. Here, we construct a new -module that is faithful for of any cardinality. For a field of arbitrary characteristic and , is studied in depth. The algebra is shown to possess a unique proper non-zero ideal, isomorphic to . This leads to a new and interesting simple algebra, , the quotient of by its unique ideal. Both and the quotient algebra are shown to have centers isomorphic to . Via the new faithful representation, all automorphisms of are shown to be inner in the sense of Definition 18.Presented by D. Passman.     

Congruences and Ideals of Effect Algebras

This paper is devoted to a general investigation of congruences and ideals in effect algebras. One of our main results is the existence of an order isomorphism between Riesz congruences and Riesz ideals. We also answer an open question of Dvureenskij and Pulmannová by showing that an ideal is a Riesz ideal if and only if it is closed under generalized Sasaki projections.     

Submonoids of Polycyclic-by-Finite Groups and their Algebras

We describe Noetherian semigroup algebras K[S] of submonoids S of polycyclic-by-finite groups over a field K. As an application, we show that these algebras are finitely presented and also that they are Jacobson rings. Next we show that every prime ideal P of K[S] is strongly related to a prime ideal of the group algebra of a subgroup of the quotient group of S via a generalised matrix ring structure on K[S]/P. Applications to the classical Krull dimension, prime spectrum, and irreducible K[S]-modules are given.     

Generalized Szasz Problems in Normal Classes of Algebras

Let A be a normal class of algebra. In the present paper, we characterize the following four problems for A: for which radical class R, there holds that(1) R(i1∧A i2) = R(i1)∧AR(i2);(2) R(i1∨i2) = R(i1)∨R(i2);(3) (i1∧i2) = i1∧i2;(4) (i1 ∨ i2) = i1 ∨ i2, for arbitrary algebra a ∈ A and any i1,i2∈La,where j denotes the ideal of a uniquely determined by R(a/j)=j/j?     

Chinese Algebras of Rank 3

The structure of the algebra K[M] of the Chinese monoid M of rank 3 over a field K is studied. The minimal prime ideals are described and the classical Krull dimension is computed. It follows that every minimal prime ideal is determined by a homogeneous congruence on M. Moreover, the prime radical is nilpotent and equal to the Jacobson radical. This ideal is not determined by a congruence on M.     

Ideal Structure of Leavitt Path Algebras with Coefficients in a Unital Commutative Ring

For a (countable) graph E and a unital commutative ring R, we analyze the ideal structure of the Leavitt path algebra L _R (E) introduced by Mark Tomforde. We first modify the definition of basic ideals and then develop the ideal characterization of Mark Tomforde. We also give necessary and sufficient conditions for the primeness and the primitivity of L _R (E), and we then determine prime graded basic ideals and left (or right) primitive graded ideals of L _R (E). In particular, when E satisfies Condition (K) and R is a field, they imply that the set of prime ideals and the set of primitive ideals of L _R (E) coincide.     

广义导子幂中心化子条件(英文)

设R是素环,U是R的极大右商环,C是R的扩展型心,I是R的非零理想,δ是R上的广义导子,a,b,q∈U.本文给出了恒等式(aδ(qx)-bx)~n=0(∈C在I上成立的充分必要条件,得到的结果推广了Herstein,Lanski,Lee的结论.     

利用格蕴涵代数找出所有LI-理想的方法

利用格蕴涵代数中理想的定义未找出所有的理想需要花费大量的时间.给出了利用格蕴涵代数的蕴涵运算表找出格蕴涵代数所有理想的方法;再利用析取运算表找出格蕴涵代数中所有sl_理想的方法;最后,利用蕴涵否运算表找出格蕴涵代数中所有LI-理想的方法.     

Nilpotent Ideals in Graded Lie Algebras and Almost Constant-Free Derivations

It is proved that if a (?/p ?)-graded Lie algebra L, where p is a prime, has exactly d nontrivial grading components and dim L ₀ = m, then L has a nilpotent ideal of d-bounded nilpotency class and of finite (m,d)-bounded codimension. As a consequence, Jacobson's theorem on constant-free nilpotent Lie algebras of derivations is generalized to the almost constant-free case. Another application is for Lie algebras with almost fixed-point-free automorphisms.     

效应代数上的态射性质

In the present paper the properties of morphisms in effect algebras are discussed. The conditions for the morphisms in effect algebras to be join-preservation and meet-preservation are given. From the categorical point of view, some properties of ideals, filters and congruence relations under morphisms are obtained.     

Approximate Identities for Ideals of Segal Algebras on A Compact Group

We show that every closed ideal of a Segal algebra on a compact group admits a central approximate identity which has the property, called condition (U), that the induced multiplication operators converge to the identity operator uniformly on compact sets of the ideal. This result extends a known one due to H. Reiter who has considered the problem under the condition that the Segal algebra is symmetric. We prove further that a closed right ideal of a Segal algebra on a compact group admits a left approximate identity satisfying condition (U) if and only if it is approximately complemented as a subspace of the Segal algebra; if in addition the Segal algebra is symmetric, then a closed left ideal admits a right approximate identity satisfying condition (U) if and only if it is approximately complemented.     

分裂的正则Hom-Leibniz-Rinehart代数

作为Hom-Leibniz代数胚的代数类比, 本文引入Hom-Leibniz-Rinehart代数的概念. 证明了分裂的正则Hom-Leibniz-Rinehart代数$L$写成$L=U+\sum_{\gamma}I_\gamma$, 其中$U$为极大交换子代数$H$的子空间和$I_\gamma$为$L$的理想, 若$[\gamma]\neq[d]$, 满足$[I_\gamma, I_d]=0$. 随后分别发展了分裂Hom-Leibniz-Rinehart代数的根和权的连通技术.最后研究了紧致的正则Hom-Leibniz-Rinehart代数的结构.