微分算子代数的一种不可约Harish-Chandra模的分类

本文首先讨论了微分算子Ｌｉｅ代数的单性，然后确定出了微分算子Ｌｉｅ代数的权重数都是１的所有不可约Ｈａｒｉｓｈ－Ｃｈａｎｄｒａ模。     

解析Toeplitz算子的强不可约性

本文得到解析Toeplitz算子的强不可约性的一个充分条件，并且刻画了换位代数的k0-群．     

Bergman空间上一类解析Toeplitz算子的强不可约性

令D为单位圆盘D={z∈C:|z|<1},L_a~2(D)为L~2(D)中解析函数构成的Bergman空间.设f(z)=a_0+a_1z+a_2z~2+…,用算子理论的技巧给出解析Toeplitz算子T_f为强不可约算子的一个充分条件.     

连续套代数中强不可约算子的酉轨道闭包

在这篇文章里,N表示连续套,且我们完全刻划了T（N）中强不可约算子的酉轨道闭包．     

sl_2(R)上Harish-Chandra模及其应用

将ｓｌ２（Ｒ）上不可约Ｈａｒｉｓｈ－Ｃｈａｎｄｒａ模及ｓｌ２（Ｒ）上不可分解的Ｈａｒｉｓｈ－Ｃｈａｎｄｒａ模进行了完全分类，得到了与ｓｌ２（Ｃ）上模分类的不同形式．作为应用，又构造了实Ｖｉｒａｓｏｒｏ代数的一类新的不可约表示．     

算子强不可约的充要条件

本文证明了Cowen-Douglas 算子是强不可约的充要条件,是它的换位代数模去其Jacobson 根同构于$H^{\infty}(D)$中的一个闭子代数,这里$D$表示开单位圆盘, $H^{\infty}(D)$表示$D$上的有界解析函数的全体.     

每个算子都是两个强不可约算子的和

本文证明了可分无穷维 Hilbert空间上每个有界线性算子均可写成两个强不可约算子之和 .这回答了文献 [9]中提出一个公开问题     

A2—有限维不可约模的权集结构

§1 基本概念 L是A_2型李代数,X={e_i,f_i,h_i;i=1,2}是L的chevalley生成元。H=是L的CSA,根系Φ={±α_1±α_2,±(α_1+α_2)},Φ~+是正根系,△={α_1,α_2}是基础根系。H~*是H的对偶空间,α_1,α_2是H~*的基。P_+={λ∈H~*,λ(h_i)∈Z~+,i=1,2}称为支配整线性函数。令λ_1,λ_2∈     

Dualizing Modules for Orders and Artin Algebras

We provide a criterion for a -bimodule to be a dualizing module, where is an order over a commutative Gorenstein complete local domain of dim R=1. Using this criterion, we give examples of dualizing modules which are neither isomorphic to nor a dual of . Thus we can also give such examples over an Artin algebra by modulo a nonzerodivisor.     

On Modules and Complexes Without Self-Extensions

Let Λ be an Artin algebra over a commutative Artinian ring, k. If M is a finitely generated left Λ -module, we denote by Ω (M) the kernel of η _M : P _M  → M a minimal projective cover. We prove that if M and N are finitely generated left Λ -modules and Ext _Λ ¹ (M, M) = 0, Ext _Λ ¹ (N, N) = 0, then M? N if and only if M/rad M? N/rad N and Ω (M)? Ω (N).

Now if k is an algebraically closed field and (d _i ) _i?? is a sequence of nonnegative integers almost all of them zero, then we prove that the family of objects X ?  ^b (Λ), the bounded derived category of Λ, with Hom ^b (Λ)(X,X[1]) = 0 and dim _k H ⁱ (X) = d _i for all i ? ?, has only a finite number of isomorphism classes (see Huisgen-Zimmermann and Saorín, 2001 Huisgen-Zimmermann , B. , Saorín , M. ( 2001 ). Geometry of chain complexes and outer automorphisms under derived equivalence . Trans. Amer. Math. Soc. 353 : 4757 – 4777 . [CSA] [CROSSREF] [Crossref], [Web of Science ®] , [Google Scholar]).     

Gorenstein-Projective Modules over Morita Rings

Let △(φ,ψ) =(A BMA ANBB) be a Morita ring which is an Artin algebra.In this paper we investigate the relations between the Gorenstein-projective modules over a Morita ring △(φ,ψ) and the algebras A and B.We prove that if △(φ,ψ) is a Gorenstein algebra and both MA and AN (resp.,both NB and BM) have finite projective dimension,then A (resp.,B) is a Gorenstein algebra.We also discuss when the CM-freeness and the CM-finiteness of a Morita ring △(φ,ψ) is inherited by the algebras A and B.     

Modules of Differential Operators on the Real Line

The space of kth-order linear differential operators on is equipped with a natural two-parameter family of structures of Diff( )-modules. To specify this family, one considers the action of differential operators on tensor densities. We give a classification of these modules.     

Differential Operators and the Steenrod Algebra

The Novikov-Landweber algebra and the Steenrod algebra are setup in terms of the primitive differential operators acting in the usual way on the integralpolynomial ring Z[x₁,... ,x_n,...]. A commutative wedge productV for differential operators is introduced and it is shown thatthe iterated wedge product is divisible by r! as an integral operator. The divided differentialoperator algebra D is generated over the integers by thedividedoperators under the wedge product. D is additively isomorphic to the abelian group ofsymmetric functions in the variables x_i. Furthermore D is closedunder composition of operators and admits a natural coproductwhich makes it a Hopf algebra in two ways, with respect to thecomposition and wedge products. Under composition D is isomorphicto the Landweber-Novikov algebra. A Hopf sub-algebra is generatedunder composition by the integral Steenrod squares and reduces mod 2 to the Steenrod algebra. An explicitproduct formula for two wedge expressions is developed and usedto derive Milnor's product formula for his basis elements inthe Steenrod algebra. The hit problem in the Steenrod algebrais reformulated in terms of partial differential operators.1991 Mathematics Subject Classification: 55S10.