广义分段Koszul代数

广义分段Koszul代数(简称为κ_p代数)一般是一类二次代数,其平凡模允许有非单纯的投射分解.利用Yoneda-Ext代数E(A)给出了分次代数A是κ_p代数的一个充分条件,同时讨论了κ_p代数的商代数是否继承κ_p性质.     

广义分段Koszul代数

广义分段Koszul代数(简称为K_p代数)一般是一类二次代数,其平凡模允许有非单纯的投射分解.利用Yoneda-Ext代数E(A)给出了分次代数A是K_p代数的一个充分条件,同时讨论了K_p代数的商代数是否继承K_p性质.     

Resolutions of Some Gorenstein Algebras with Nonunimodal Hilbert Functions

Given a compressed Artin level algebra A which satisfies certain properties, it is possible to use this algebra to construct a Gorenstein Artin algebra with a nonunimodal Hilbert function. We show how to construct a minimal free resolution for these algebras, using the minimal free resolution of A.     

Projective Resolutions and Yoneda Algebras for Algebras of Dihedral Type

This paper provides a method for the computation of Yoneda algebras for algebras of dihedral type. The Yoneda algebras for one infinite family of algebras of dihedral type (the family in K. Erdmann’s notation) are computed. The minimal projective resolutions of simple modules were calculated by an original computer program implemented by one of the authors in C++ language. The algorithm of the program is based on a diagrammatic method presented in this paper and inspired by that of D. Benson and J. Carlson. This work was partially supported by the grant 06-01-00200 of the Russian Foundation for Basic Research.     

QF代数的Hopf代数作用

Ｈ是 Ｈｏｐｆ代数，Ａ是左 Ｈ－模代数，本文给出了当 Ａ是 ＱＦ代数时，ＡＨ也是 ＱＦ代数的一个条件．     

Structure Theorems for Bicomodule Algebras Over Quasi-Hopf Algebras,Weak Hopf Algebras,and Braided Hopf Algebras

Let H be a quasi-Hopf algebra, a weak Hopf algebra, or a braided Hopf algebra. Let B be an H-bicomodule algebra such that there exists a morphism of H-bicomodule algebras v: H → B. Then we can define an object B^co(H), which is a left-left Yetter–Drinfeld module over H, having extra properties that allow to make a smash product B^co(H)#H, which is an H-bicomodule algebra, isomorphic to B.     

On the Simplicity of Lie Algebras Associated to Leavitt Algebras

For any field 𝕂 and integer n ≥ 2, we consider the Leavitt algebra L _𝕂(n); for any integer d ≥ 1, we form the matrix ring S = M _d (L _𝕂(n)). S is an associative algebra, but we view S as a Lie algebra using the bracket [a, b] = ab ? ba for a, b ∈ S. We denote this Lie algebra as S ^?, and consider its Lie subalgebra [S ^?, S ^?]. In our main result, we show that [S ^?, S ^?] is a simple Lie algebra if and only if char(𝕂) divides n ? 1 and char(𝕂) does not divide d. In particular, when d = 1, we get that [L _𝕂(n)^?, L _𝕂(n)^?] is a simple Lie algebra if and only if char(𝕂) divides n ? 1.     

Hopf-Type Algebras

In this article, we provide an alternative approach to the definition of a weak Hopf algebra (WHA). For an associative unital algebra A with a coassociative comultiplication Δ ∈Alg ^u (A, A ? A), the set of homomorphisms from A to A ? A, which do not preserve the units. If the linear maps Ξ₁, Ξ₂ ∈ End(A ? A), defined by Ξ₁(a ? b) = Δ(a)(1 ? b), Ξ₂(a ? b) = (a ? 1)Δ(b), are von Neumann regular elements in the ring End(A ? A) of endomorphisms of A ? A satisfying some appropriate assumptions, we call the A a Hopf-type algebra. We show the existence of a target, a source, a counit, and an antipode of A as in the usual WHA.     

Vertex Poisson Algebras Associated with Courant Algebroids

We study relationships between vertex Poisson algebras and Courant algebroids. For any ?-graded vertex Poisson algebra A = ? _n∈? A _(n), we show that A ₍₁₎ is a Courant A ₍₀₎-algebroid. On the other hand, for any Courant 𝒜-algebroid ?, we construct an ?-graded vertex Poisson algebra A = ? _n∈? A _(n) such that A ₍₀₎ is 𝒜 and the Courant 𝒜-algebroid A ₍₁₎ is isomorphic to ? as a Courant 𝒜-algebroid.     

具有分解性质的次对角代数

设M是σ-有限的von Neumann代数,21是M的具有分解性质的次对角代数,即对任意可逆算子T∈M,都存在西算子U∈M及可逆算子A∈21∩21~(-1),使得T=UA,本文证明了21的代数换位是自伴的,同时也证明了21中的可逆算子群是σ-弱连通集。     

拟遗传Nakayama代数

本文分别给出了拟遗传Nakayama代数和拟遗传左serial代数的整体维数等于2或3的充分条件。     

关于格上蕴涵代数及其对偶代数

给出了格蕴涵代数、MV代数、R₀代数等一些格上蕴涵代数之间的关系,并建立了它们的对偶代数.其结果描述了这些代数内部结构的特征,同时也为从语义的角度进一步研究格值逻辑系统提供了一个新的途径.     

Degenerations of Jordan Algebras and"Marginal"Algebras

We describe all degenerations of the variety(3)ot?3 of Jordan algebras of di-mension three over C.In particular,we describe all irreducible components in(3)ot?3.For every n we define an n-dimensional rigid"marginal"Jordan algebra of level one.Moreover,we discuss marginal algebras in associative,alternative,left alternative,non-commutative Jordan,Leibniz and anticommutative cases.     

Standardly Stratified Extension Algebras

Abstract

The paper generalizes some of our previous results on quasi-hereditary Koszul algebras to graded standardly stratified Koszul algebras. The main result states that the class of standardly stratified algebras for which the left standard modules as well as the right proper standard modules possess a linear projective resolution – the so called linearly stratified algebras – is closed under forming their Yoneda extension algebras. This is proved using the technique of Hilbert and Poincaré series of the corresponding modules.

     

On Restricted Leibniz Algebras

ABSTRACT

The role played by fields in relation to Galois Rings corresponds to semifields if the associativity is dropped, that is, if we consider Generalized Galois Rings instead of (associative) Galois rings. If S is a Galois ring and pS is the set of zero divisors in S, S* = S\ pS is known to be a finite {multiplicative} Abelian group that is cyclic if, and only if, S is a finite field, or S = ?/n? with n = 4 or n = p ^r for some odd prime p. Without associativity, S* is not a group, but a loop. The question of when this loop can be generated by a single element is addressed in this article.     

广义路代数与点Hopf代数

Most of pointed Hopf algebras of dimension p^m with large coradtical are shown to be generalized path algebras. By the theory of generalized path algebras, the representations, homological dimensions and radicals of these Hopf algebras are obtained. The relations between the radicals of path algebras and connectivity of directed graphs are given.     

Triangular Decomposition of Composition Algebras of Domestic Canonical Algebras

Let A be a domestic canonical algebra over a finite field. In this article, we prove that the composition algebra C(A) of A has a triangular decomposition 𝒫·𝒯·? corresponding to the division of the indecomposable modules into the preprojectives, the regulars, and the preinjectives.     

格蕴涵代数与BCK代数的关系

本文给出了有界可换的ＢＣＫ代数的分配性的一些等价条件，指出了格蕴涵代数与有界可换分配的ＢＣＫ代数以及格Ｈ蕴涵代数与有界关联的ＢＣＫ代数之间的对偶关系     

Deformations of Quadratic Algebras with Antisymmetric Relations

A finitely generated quadratic algebra with antisymmetric generating relations is called a weakly symmetric algebra. The automorphism group and Calabi–Yau property of a Poincaré–Birkhoff–Witt (PBW)-deformation of a weakly symmetric algebra are discussed. It is shown that the Calabi–Yau property of a PBW-deformation of a weakly symmetric algebra is equivalent to that of the corresponding augmented PBW-deformation under some mild conditions.