G-旋模型场代数中的对偶定理

设Ｇ是有限群，　Ｈ是Ｇ的子群，Ｄ（Ｇ）为Ｇ的Ｄｏｕｂｌｅ代数，　Ｆ是　Ｇ－旋模型所对应的场代数．　本文考虑Ｄ（Ｇ）的Ｈｏｐｆ子代数Ｄ（Ｈ），证明了Ｆ的Ｄ（Ｈ）不变子空间ＡＨ是Ｃ＊－代数．Ｄ（Ｈ）存在Ｃ＊－表示，使得Ｄ（Ｈ）和ＡＨ互为换位子．     

一种上同调系同态的实现

设Ｍ，Ｎ是两个单连通的闭流形，ｆ：Ｍ→Ｎ是同伦等价．本文利用过去的一个结论，定义了一个上同调系同构Ｈ＊（Ｎ＊；Ｇ）→（Ｍ＊；Ｇ），其中Ｍ＊，Ｎ＊分别是血与Ｎ的去核乘积．然后，运用周学光引入的特征上同调运算于，证明了在某些情形下，有几何实现，从而Ｍ＊与Ｎ＊同伦等价．     

左不变作用生成的Groupoid C~＊－代数动力系统

本文引进了由左不变作用生成的ＧｒｏｕｐｏｉｄＣ＊－代数动力系统．研究了它与由１－ｃｏｃｙｃｌｅ生成的ＧｒｏｕｖｏｉｄＣ＊－代数动力系统的关系．得到了两个共变同构定理及两个对偶定理．     

3-空间曲面上的一个重要向量场及相关结果

设 ｆ：Ｍ２（Ｃ）→ Ｎ３（ｃ）是 ２－维黎曼流形 Ｍ２到 ３维空间形式 Ｎ３（Ｃ）的等距浸入．找到一个由Ｍ２的第二基本形式确定的向量场 δ ，使得高斯曲率 Ｋ表为其散度 Ｋ＝ ｄｉｖ（δ）．在 Ｎ３（ｃ）＝ Ｅ３的情形，证明了ｆ可保持反定向高斯映射共形形变的充要条件是δ为闭向量场．对于可保持反定向高斯映射共形形变的曲面，本文给出了其形变象的表示公式     

ON Δ-GOOD MODULE CATEGORIES OF QUASI-HEREDITARY ALGEBRAS

ＯＮΔ┐ＧＯＯＤＭＯＤＵＬＥＣＡＴＥＧＯＲＩＥＳＯＦＱＵＡＳＩ┐ＨＥＲＥＤＩＴＡＲＹＡＬＧＥＢＲＡＳ＊＊ＤＥＮＧＢＡＮＧＭＩＮＧ＊ＸＩＣＨＡＮＧＣＨＡＮＧ＊ＭａｎｕｓｃｒｉｐｔｒｅｃｅｉｖｅｄＪｕｎｅ１２，１９９５．ＲｅｖｉｓｅｄＭａｙ３，１９９６．...     

布尔矩阵广义逆A－ω，A－d，A－ω

设Ａ是布尔矩阵，而矩阵Ｇ满足ＡＧＡ＝Ａ．（１）如果对所有Ａｘ＝ｙ的向量ｘ，ｙ．有ω（Ｇｙ）≤ω（ｘ）（＊）称Ｇ是Ａ的一个极小权ｇ－逆，表示为Ａ－ω．（２）如果对所有向量ｘ，ｙ，有ｄ（ＡＧｙ，ｙ）≤ｄ（Ａｘ，ｙ）（＊＊）称Ｇ是Ａ的最小距离ｇ－逆，表示为Ａ－ｄ．（３）如果（＊）和（＊＊）都成立，就称Ｇ是极小权最小距离ｇ－逆，表示为Ａ－ωｄ．本文研究这三类广义逆矩阵的最大逆的存在性及表示式．主要结果如下：假定对于矩阵Ａ．Ａ－ω，Ａ－ｄ，Ａ－ωｄ分别存在，那么．（１）存在最大Ａ－ω，当且仅当Ａ中设有两个相同的非零列，且最大Ａ－ω为Ａω＝［ＩＣＡＴ］Ｃ．（２）最大Ａ－ｄ存在，且为Ａｄ＝［ＡＴＡＣＡＴ＋ＡＴ（ＪＡＴ）Ｃ］Ｃ．（３）存在最大Ａ－ωｄ，当且仅当Ａ的所有非零列向量线性独立，且最大Ａ－ωｄ为Ａωｄ＝［ＡＴＡｃＡＴ＋ＡＴ（ＪＡＴ）ｃ＋（ＡＴＪ）ｃＡＴ］Ｃ．其中Ｊ为全１矩阵     

带弦的圈是协调图

称具有ｅ条边的简单图Ｇ为协调图，若存在由Ｇ的顶点集到模ｅ的整数群Ｚｅ的一个单射ｈ，使得导出映射ｈ＾＊：ｈ＾＊（ｕｖ）≡ｈ（ｕ）＋ｈ（ｖ）（ｍｏｄ ｅ）是一个由Ｇ的边集到Ｚｅ的双射，带弦的圈Ｃ′ｎ是由含ｎ个顶点的圈Ｃｎ上添一条连结两个不相邻顶点的边而得到的图。本文中证明了，除了ｎ＝６且弦端点在Ｃｎ上的距离为２的情况外，所有带弦的圈都是协调图。     

论优化问题的公理方法（Ⅰ）

π－簇表示论域Ω上具有性质π的集合簇：≠；当Ａ，Ｂ∈，Ｂ∈，ＸＡ，总有Ｘ，Ａ∪Ｂ∈．定义２在π－簇上，＊是优化算子，如果公理１Ａ对应唯一的子集合Ａ＊．写Ａ＝Ａ＊∪，Ａ＊∩Ａ＝；公理２；．定义３在定义２中，还满足公理３若ＡＣ，则ＡＣ；公理４（Ａ＊∪Ｂ）＊（Ａ∪Ｂ），则说算子＊是上的第一类优化算子．对此，建立了两个优化原理，还给出了几个关于这种算子＊的例子．     

幺模群上的不可分解正定函数及其应用

本文得到了么模群Ｇ上酉表示的不可约性的一个等价刻画．即若ｆ是Ｇ上正定函数,π是Ｇ在Ｈｉｌｂｅｒｔ空间Ｈ上的酉表示,ｕ∈Ｈ是 Ｈ的拓扑生成元且ｆ（ｘ）＝（π（ｘ）ｕ,ｕ）,则ｆ是不可分解的正定函数的充要条件是π是不可约酉表示．并将这一结果应用到ＳＵ（２）,ＳＬ（２,Ｒ）上．     

复射影空间的等参子流形

本文给出了复射影空间Ｐ＿ｎ（Ｃ）上的等参映射定义，并证明了等参映射ｆ在Ｈｏｐｆ主丛π：Ｓ￣（２ｎ＋１）→Ｐ＿ｎ（Ｃ）下的水平提升为Ｓ￣（２ｎ＋１）的等参映射。同时，利用对称空间的表示给出了Ｐ＿ｎ（Ｃ）上等参子流形的例子．     

The Hochschild cohomology of a closed manifold

Let M be a closed orientable manifold of dimension d and be the usual cochain algebra on M with coefficients in a field k. The Hochschild cohomology of M, is a graded commutative and associative algebra. The augmentation map induces a morphism of algebras . In this paper we produce a chain model for the morphism I. We show that the kernel of I is a nilpotent ideal and that the image of I is contained in the center of , which is in general quite small. The algebra is expected to be isomorphic to the loop homology constructed by Chas and Sullivan. Thus our results would be translated in terms of string homology.     

Maximum Principle of Semi-Linear Distributed System (I)

In this paper, an optimal control problem of non-linear Volterra systems $x(\cdot)=h(t)+\int_0^t G(t,s)f(s,x(s),u(s))ds$ on Banach space X with a general cost functional $Q(u(\cdot)) = \int_0^T J(s,x(s,u(\cdot)),u(s))ds$ is discussed, where $G(t,s)\in \varphi(X)$ is strongly continuous in (t, s), h(\cdot)\in C([0,T],G),f(s,x,u):[0,T]*X*U \rightarrow X and J (s, x, u) : [0, T] *X*U \rightarrow R. The control region U is an arbitrary set in a Banach space. Under some other assumptions of f and J, we have proved the following Theorem. The optimal control u^*(\cdot) of the above problem satisfies max $H(t,u)=H(t,u^*(t))$ for a.e.t\in [0,T], Where $H(t,u)=-J(t,x^*(t),u)+(\phi(t),f(t,x^*(t),u))$, $\phi(t)=\int_t^T J_x(s,x^*(s),u^*(s))U(s,t)ds$ and $x^*(t)=x(t,u^*(\cdot)),U(s,t)\in \phi(X)$ is the solution of $U(s,t)=G(s,t)+\int _t^s G(s,w)f_x(w,x^*(w),u^*(w))U(w,t)dw$. We have applied the results to semi-linear distributed systems.     

Orbifold index and equivariant <Emphasis Type="Italic">K</Emphasis>-homology

Let G be countable group and M be a proper cocompact even-dimensional G-manifold with orbifold quotient . Let D be a G-invariant Dirac operator on M. It induces an equivariant K-homology class and an orbifold Dirac operator on . Composing the assembly map with the homomorphism given by the representation of the maximal group C ^*-algebra induced from the trivial representation of G we define index . In the second section of the paper we show that index = index([D]) and obtain explicit formulas for this integer. In the third section we review the decomposition of in terms of the contributions of fixed point sets of finite cyclic subgroups of G obtained by W. Lück. In particular, the class [D] decomposes in this way. In the last section we derive an explicit formula for the contribution to [D] associated to a finite cyclic subgroup of G.     

非自伴算子代数间的等距代数同构

设Ｇｉ是满足第二可数性公理的、Ｈａｕｓｄｏｒｆｆ的、顺从的、ｒ－离散的、主的局部紧群胚，并且有一个紧开Ｇ－集覆盖；设Ｐｉ是Ｇｉ中含Ｇ＿ｉ￣０的开闭集，且满足及相应的模是具有性质ＤＣ的Ｃ（Ｇｉ）的子代数（ｉ＝１，２）．本文证明从Ａ（Ｐ１）到Ａ（Ｐ２）上的每一个等距代数同构可以扩张成从Ｃ（Ｇ１）到Ｃ（Ｇ２）上的Ｃ－同构，进一步，可以对Ｃ（Ｇ２）重新坐标化，使得这个Ｃ－同构可由一个群胚同构生成．     

Some notes on amenability and weak amenability of Lau product of Banach algebras defined by a Banach algebra morphism

Let A and B be Banach algebras and T : B → A be a continuous homomorphism. nweak amenability of the Banach algebra A ×T B(defined in Bade, W. G., Curtis, P. C., Dales, H. G.:Amenability and weak amenability for Beurling and Lipschitz algebras. Proc. London Math. Soc.,55(2), 359–377(1987)) is studied. The new version of a Banach algebra defined with a continuous homomorphism is introduced and Arens regularity and various notions of amenability of this algebra are studied.     

Realization of the mapping class group by homeomorphisms

In this paper, we show that the mapping class group of a closed surface can not be geometrically realized as a group of homeomorphisms of that surface. More precisely, let denote the standard projection of the group of homeomorphisms to the mapping class group of a closed surface M of genus g>5. We show that there is no homomorphism , such that is the identity. This answers a question by Thurston (see [11]). Mathematics Subject Classification (2000)  Primary 20H10, 37F30     

On Products of $$\mathrm{F}^*(G)$$ -Subnormal Subgroups of Finite Groups

Mathematical Notes - A subgroup $$H$$ of a finite group $$G$$ is said to be $$\mathrm{F}^*(G)$$ -subnormal if it is subnormal in $$H\mathrm{F}^*(G)$$ , where $$\mathrm{F}^*(G)$$ is the generalized...     

标准算子代数上的Jordan映射

Let A be a standard operator algebra on a Banach space of dimension 〉 1 and B be an arbitrary algebra over Q the field of rational numbers. Suppose that M ： A → B and M^＊ ： B → A are surjective maps such that {M（r（aM^＊（x）＋M^＊（x）a））=r（M（a）x＋xM（a））, M^＊（r（M（a）x＋xM（a）））=r（aM^＊（x）＋M^＊（x）a） for all a ∈ A, x ∈ B, where r is a fixed nonzero rational number. Then both M and M^＊ are additive.     

具有阿贝尔Sylow 2-子群的有限群的整群环的正规化子性质

Mazur猜想:具有阿贝尔Sylow 2-子群的有限群有正规化子性质.设G是一个有限群,N是G的一个正规子群且Z(G/N)仅有平凡单位,本文建立了由Z(G/N)中单位诱导的G的自同构与N的Coleman自同构之间的联系,在此基础上证明了若G是一个具有阿贝尔Sylow 2-子群的有限群且Z(G/F*(G))仅有平凡单位,则Mazur猜想对G成立.