N(2,2,0)代数的T-模糊子代数和T-模糊理想

为了深入研究N(2,2,0)代数的代数结构,在N(2,2,0)代数中引入了T模糊子代数和T模糊理想的概念,进一步讨论了它们的性质.分别给出了N(2,2,0)代数的模糊子代数和模糊理想与子代数和理想的关系.证明了N(2,2,0)代数的两个T模糊子代数的模交也是T模糊子代数,而N(2,2,0)代数的两个T模糊理想的模交也是T模糊理想.     

N(2,2,0)代数的E-反演半群

本文研究了N(2,2,0)代数(S,*,△,0)的E-反演半群.利用N(2,2,0)代数的幂等元,弱逆元,中间单位元的性质和同宇关系,得到了N(2,2,0)代数的半群(S,*)构成E-反演半群的条件及元素α的右伴随非零零因子唯一,且为α的弱逆元等结论,这些结果进一步刻画了N(2,2,0)代数的结构.     

关于N（2，2，0）代数的中间幂等元

为了深入研究N（2,2,0）代数的代数结构,在N（2,2,0）代数中建立了中间幂等元的概念,讨论了它的基本性质,给出了中间幂等元关联的集合坞是（S,＊,△,0）的子代数的一个条件．证明了当U（2,2,0）代数中包含一个右零半群时,Mg是幂等元集E（S）的子集．并利用坞定义了一个等价关系．     

N(2,2,0)代数中平移变换的象与逆象

作为可约化半群的推广,引入了半群左(右)可约化的概念,讨论了N(2,2,0)代数中三类平移变换的象、逆象的代数结构.     

双重半伪补MS代数的正则滤子

正则滤子是刻画代数结构的工具,借助正则滤子同余关系有助于了解代数的内部结构.首先在双重半伪补MS代数上,引入正则滤子的概念,结合双重半伪补MS代数的运算属性,构造出具有正则滤子的最大同余关系;其次,利用双重半伪补MS代数具有正则滤子最小同余关系表达式,给出了具有正则滤子的最小同余关系与最大同余关系的等式关系.所得结论为其它分配格代数类正则滤子性质的研究提供了方法,丰富了分配格理论,为进一步研究分配格代数类的代数结构提供理论支持.     

关于N(2,2,0)代数的软理想

本文将软集引入到N(2,2,0)代数,给出了软理想、软关联理想、软正关联理想的概念,讨论了它们之间的相互关系;得到了N(2,2,0)代数的软理想、软关联理想和软正关联理想的等价刻画,并研究了它们在软集运算下的若干基本性质;最后,探讨了软理想的像与原像的基本性质。     

FI代数的模糊滤子

在FI代数(Fuzzy蕴涵代数)上引入了模糊滤子的概念并给出了其等价刻画；探讨了由模糊滤子所诱导的同余关系及商代数,证明了由模糊滤子所诱导的同余关系是完备分配格.     

双重半伪补MS代数的滤子同余关系

在双重半伪补MS代数上引入余核滤子的概念,构造了余核滤子同余关系表达式,获得了余核滤子判别定理.根据双重半伪补MS代数的运算特征及主同余表示理论,获得了余核滤子同余关系的若干等价表达式并证明了双重半伪补MS代数余核滤子与其同余关系是同构的.所得结论为Ockham代数类余核滤子性质的研究提供了方法,丰富了序代数结构理论.     

伪补MS-代数的同余关系

本文研究了伪补MS-代数的同余关系.利用正则滤子和伪补代数的对偶窄间理论,得到了正则滤子所生成的同余关系的性质以及同余可换的伪补MS-代数类,从而推广了文献[9]的结果.     

N(2,2,0)代数的(∈,∈∨q_(λ,μ))-模糊关联理想

从以下几个方面对N(2,2,0)代数(∈,∈∨q_((λ,μ)))-模糊关联理想进行了详细的研究.首先,给出N(2,2,0)代数广义模糊关联理想概念和点态化(∈,∈∨q_((λ,μ)))-模糊关联理想概念,研究了两者之间的等价关系;其次,给出了(∈,∈∨q_((λ,μ)))-模糊关联理想若干等价刻画;再次,讨论了(∈,∈∨q_((λ,μ)))-模糊关联理想与(∈,∈∨q_((λ,μ)))-模糊理想之间的关系;最后,获得了(∈,∈∨q_((λ,μ)))-模糊关联理想交与并的相关性质.     

Algebraic coalitions

The idea of an algebra in is introduced. Within congruence modular varieties such algebras are shown to be the abelian algebras with a one-element subalgebra. This leads on to the notion of algebraic coalition, which is characterized for congruence modular varieties and for varieties of Jónsson–Tarski algebras. This characterization displays an intimate relationship between algebraic coalitions, Gumm difference terms, and the centre of an algebra. Received July 16, 1996; accepted in final form May 2, 1997.     

A note on atomistic weak congruence lattices

It is proved that a codistributive element in an atomistic algebraic lattice has a complement, implying that kernels of the related homomorphisms coincide. Some applications to weak congruence lattices of algebras are presented. In particular, necessary and sufficient conditions under which the weak congruence lattice of an algebra is atomistic are given.     

Non-representable distributive semilattices

We present two examples of distributive algebraic lattices which are not isomorphic to the congruence lattice of any lattice. The first such example was discovered by F. Wehrung in 2005. One of our examples is defined topologically, the other one involves majority algebras. In particular, we prove that the congruence lattice of the free majority algebra on (at least) ℵ₂ generators is not isomorphic to the congruence lattice of any lattice. Our method is a generalization of Wehrung’s approach, so that we are able to apply it to a larger class of distributive semilattices.     

Hecke algebras from groups acting on trees and HNN extensions

We study Hecke algebras of groups acting on trees with respect to geometrically defined subgroups. In particular, we consider Hecke algebras of groups of automorphisms of locally finite trees with respect to vertex and edge stabilizers and the stabilizer of an end relative to a vertex stabilizer, assuming that the actions are sufficiently transitive. We focus on identifying the structure of the resulting Hecke algebras, give explicit multiplication tables of the canonical generators and determine whether the Hecke algebra has a universal $C^1$-completion. The paper unifies algebraic and analytic approaches by focusing on the common geometric thread. The results have implications for the general theory of totally disconnected locally compact groups.     

Noncommutative two-dimensional topological field theories and Hurwitz numbers for real algebraic curves

It is well known that the classical two-dimensional topological field theories are in one-to-one correspondence with the commutative Frobenius algebras. An important extension of classical two-dimensional topological field theories is provided by open-closed two-dimensional topological field theories. In this paper we extend open-closed two-dimensional topological field theories to nonorientable surfaces. We call them Klein topological field theories (KTFT). We prove that KTFTs bijectively correspond to (in general noncommutative) algebras with certain additional structures, called structure algebras. The semisimple structure algebras are classified. Starting from an arbitrary finite group, we construct a structure algebra and prove that it is semisimple. We define an analog of Hurwitz numbers for real algebraic curves and prove that they are correlators of a KTFT. The structure algebra of this KTFT is the structure algebra of a symmetric group.     

李代数W(2,2)上的Hom-李代数结构

李代数W（2，2）是一类重要的无限维李代数，它是在研究权为2的向量生成的顶点算子代数的过程当中提出来的.Hom-李代数是指同时具备代数结构和李代数结构的一类代数，并且乘法与李代数乘法运算满足Leibniz法则.本文确定了李代数W（2，2）上的Hom-李代数结构.主要结论是李代数W（2，2）上没有非平凡的Hom-李代数结构.本文的研究结果对于W（2，2）代数的进一步研究有一定的帮助作用.     

Weyl代数研究简介

本文简要综述Ｗｅｙｌ代数诞生７０余年来的一系列重要研究成果。     

Projective algebras and primitive subquasivarieties in varieties with factor congruences

We prove that in the varieties where every compact congruence is a factor congruence and every nontrivial algebra contains a minimal subalgebra, a finitely presented algebra is projective if and only if it has every minimal algebra as its homomorphic image. Using this criterion of projectivity, we describe the primitive subquasivarieties of discriminator varieties that have a finite minimal algebra embedded in every nontrivial algebra from this variety. In particular, we describe the primitive quasivarieties of discriminator varieties of monadic Heyting algebras, Heyting algebras with regular involution, Heyting algebras with a dual pseudocomplement, and double-Heyting algebras.     

Forms and Baer ordered *-fields

It is well known that for a quaternion algegra, the anisotropy of its norm form determines if the quaternion algebra is a division algebra. In case of biquaternio algebra, the anisotropy of the associated Albert form (as defined in [LLT]) determines if the biquaternion algebra is a division ring. In these situations, the norm forms and the Albert forms are quadratic forms over the center of the quaternion algebras; and they are strongly related to the algebraic structure of the algebras. As it turns out, there is a natural way to associate a tensor product of quaternion algebras with a form such that when the involution is orthogonal, the algebra is a Baer ordered *-field iff the associated form is anisotropic.