Low Dimensional Cohomology of Hom-Lie Algebras and q-deformed W（2, 2） Algebra

This paper aims to study low dimensional cohomology of Hom-Lie algebras and the qdeformed W(2, 2) algebra. We show that the q-deformed W(2, 2) algebra is a Hom-Lie algebra. Also,we establish a one-to-one correspondence between the equivalence classes of one-dimensional central extensions of a Hom-Lie algebra and its second cohomology group, leading us to determine the second cohomology group of the q-deformed W(2, 2) algebra. In addition, we generalize some results of derivations of finitely generated Lie algebras with values in graded modules to Hom-Lie algebras.As application, we compute all αk-derivations and in particular the first cohomology group of the q-deformed W(2, 2) algebra.     

双参数量子群GLp,q（2）及其上量子de Rham复形

量子群起源于理论物理,与数学的许多分支和一些重要的物理模型关系十分密切。因此,近几年来量子群理论已经广泛地引起了数学家和物理学家的研究兴趣,发展十分迅速。其中,量子群微分运算方面的几何理论是首先由Woronowicz讨论的,随后,Wess,Zumino和Manin对更一般的量子群和相应的量子空间上的微分运算做了更深入的讨论。在文献[11]中,A.Schirrmacher,J.Wess & B.Zumino讨论了双参     

Matching Realization of Uq（sln＋1） of Higher Rank in the Quantum Weyl Algebra Wq（2n）

In the paper, we further realize the higher rank quantized universal enveloping algebra Uq（sln＋1） as certain quantum differential operators in the quantum Weyl algebra Wq （2n） defined over the quantum divided power algebra Sq（n） of rank n. We give the quantum differential operators realization for both the simple root vectors and the non-simple root vectors of Uq（sln＋1）. The nice behavior of the quantum root vectors formulas under the action of the Lusztig symmetries once again indicates that our realization model is naturally matched.     

Quantizations of the W-Algebra W（2, 2）

We quantize the W-algebra W(2, 2), whose Verma modules, Harish-Chandra modules, irreducible weight modules and Lie bialgebra structures have been investigated and determined in a series of papers recently.     

（Co）Homology and Universal Central Extension of Hom-Leibniz Algebras

Hom-Leibniz algebra is a natural generalization of Leibniz algebras and Hom-Lie algebras. In this paper, we develop some structure theory (such as (co)homology groups, universal central extensions) of Hom-Leibniz algebras based on some works of Loday and Pirashvili.     

Cohomologies of Leibniz Algebras with Higher Derivations北大核心CSCD

本文研究具有高阶导子的莱布尼兹代数.我们称之为LeibHDer对.首先给出LeibHDer对的表示并构造半直积.最后,定义LeibHDer对的上同调并研究其中心扩张和形变理论.     

Von Neumann Algebras Associated with the Group SL2（R）

Let M\mathcal{M} and N\mathcal{N} be the von Neumann algebras induced by the rational action of the group SL ₂(ℝ) and its subgroup P on the upper half plane \mathbbH\mathbb{H}. We have shown that N\mathcal{N} is spatial isomorphic to the group von Neumann algebra L_P\mathcal{L}_P and characterized M\mathcal{M} and its commutant M￠\mathcal{M}' and gotten a generalization of the Mautner’s lemma. It is also shown that the Berezin operator commutates with the Laplacian operator.     

量子环面李代数的自同构群, 泛中心扩张与导子

C_q:=C_q[x^±1₁, x^±1₂] 为复数域上的量子环面, 其中q≠ 0是一个非单位根, D(C_q) 为C_q的导子李代数. 记L_q 为C_q ㈩ D(C_q)的导出子代数. 该文研究李代数L_q的自同构群, 泛中心扩张和导子李代数.     

量子环面李代数的自同构群,泛中心扩张与导子

Cq=Cq[x1^±1,x2^±1]为复数域上的量子环面，其中q≠0是一个非单位根，D（Cq）为Cq的导子李代数．记Lq为Cq＋D（Cq）的导出子代数．该文研究李代数Lq的自同构群，泛中心扩张和导子李代数．     

On the Indecomposable Modules of Uq（sl（2）） Constructed via Ore-extension

Let A be a subalgebra of Uq (sl(2)) generated by K, K-1 and F and Aδ be a subalgebra of Uq (sl(2)) generated by K, K-1 (and also Fd if q is a primitive d-th root of unity with d an odd number). Given an Aδ -module M, a Uq (sl(2))-module AAδ M is constructed via the iterated Ore extension of Uq (sl(2)) in a unified framework for any q. Then all the submodules of AAδ M are determined for a fixed finite-dimensional indecomposable Aδ -module M . It turns out that for some indecomposable Aδ -module M , the Uq (sl(2))-module AAδ M is indecomposable, which is not in the BGG-categories Oq associated with quantum groups in general.     

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.     

Dual Lie Bialgebra Structures of W -algebra W (2, 2) Type

In the present paper, we investigate the dual Lie coalgebras of the centerless W(2, 2) algebra by studying the maximal good subspaces. Based on this, we construct the dual Lie bialgebra structures of the centerless W(2, 2) Lie bialgebra. As by-products, four new infinite dimensional Lie algebras are obtained.     

Remarks on Nonassociative Structures in Quantum Projective Field Theory: the Central Extension jl(2,C) of the Double sl(2,C)+sl(2,C) of the Simple Lie Algebra sl(2,C) and Related Topics

This paper is a revised and expanded version of two notes devoted to nonassociative structures in quantum projective field theory.     

Universal Central Extensions of Lie Groups

We call a central Z-extension of a group G weakly universal for an Abelian group A if the correspondence assigning to a homomorphism ZA the corresponding A-extension yields a bijection of extension classes. The main problem discussed in this paper is the existence of central Lie group extensions of a connected Lie group G which is weakly universal for all Abelian Lie groups whose identity components are quotients of vector spaces by discrete subgroups. We call these Abelian groups regular. In the first part of the paper we deal with the corresponding question in the context of topological, Fréchet, and Banach–Lie algebras, and in the second part we turn to the groups. Here we start with a discussion of the weak universality for discrete Abelian groups and then turn to regular Lie groups A. The main results are a Recognition and a Characterization Theorem for weakly universal central extensions.     

一类量子环面李代数的泛中心扩张

设Cq=Cq[x1^±1,x2^1]为复数域上的量子环面,其中q≠0是一个非单位根．D（Cq）为Cq的导子李代数．记Lq为Cq＋D（Cq）的导出子代数．本文研究李代数Lq的泛中心扩张．     

中心为4的8维幂零李代数的分类

In this paper, we give a complete classification of eight dimensional nilpotent Lie algebras with four-dimensional center by using the method of Skjelbred and Sund.     

Class of representations of skew derivation Lie algebra over quantum torus

Let L be the skew derivation Lie algebra of the quantum torus ℂ_q. In this paper, we give a class of irreducible representations for L with infinite dimensional weight spaces.      

Central extensions of some Lie algebras

We consider three Lie algebras: , the Lie algebra of all derivations on the algebra of formal Laurent series; the Lie algebra of all differential operators on ; and the Lie algebra of all differential operators on We prove that each of these Lie algebras has an essentially unique nontrivial central extension.