极大代数上有限生成模的凸性

研究极大代数上有限生成模的凸性.基于极大代数上有限生成模的几何形态,运用代数与几何方法,分析空间维数n≤3和生成向量数m≥1的有限生成模的凸性.证明n=1,2的有限生成模是凸集.对于n=3,给出m=2的有限生成模为凸集的一个充分必要条件,以及m≥3的有限生成模为凸集的一个充分条件.此外,对于极大代数上有限生成模的几何形态,发现n=3,m≥3的形态有三种情形.     

Abel群环上的有限生成投射模

本文得到了有限生成投射ＲＧ－模为自由的充要条件，这里Ｂ为遗传环、零维环以及某些幂级数环，Ｇ为有限生成的Ａｂｅｌ群．     

m-重代数A~((m))上的倾斜模

设A是代数闭域k上的有限维遗传代数,A~((m))和ζ_m(A)分别是A的m-重代数和m-丛范畴.众所周知,代数A~((m))的投射维数不超过m的基本的(basic)倾斜模与m-丛范畴ζ_m(A)的基本的倾斜对象一一对应,这是本文进一步研究m-重代数的倾斜模的原因.本文综述m-重代数A~((m))的偏倾斜模的补、倾斜箭图、倾斜模的自同态代数以及生成子-余生成子的自同态代数的整体维数的值分布.     

三次幻方的构作

给出2k维m阶t次幻方及m模方阵,m模列满秩矩阵,模线,m经典模线集和t次m模基因阵的概念,并用矩阵法和组合法初步研究了t次幻方特别是三次幻方的构作.证明:(i)若存在2k阶t次m模基因阵,则存在2k维m阶t次幻方;(ii)若N=P1α1P2α2…PSαS为N的标准分解式,iα≥3,Piiα≥16(1≤i≤S),则存在二维N阶三次幻方;(iii)若存在二维偶m阶2t+1次幻方和二维n阶2t次幻方,则存在二维mn阶2t+1次幻方;(iv)若存在二维m阶和n阶t次幻方,则存在二维mn阶t次幻方;(v)当t≥3时,不存在二维单偶数阶t次幻方.     

线性群中的一类可解完全群

设 m 为奇数(m≥3),模 m 剩余类环 Zm 内的全体可逆元组成的集合记为 Zm~*。我们定义的 n 级(n=2v,v≥2)线性群 G 是由如下形式的辛矩阵生成的     

Tame 遗传代数导出的 Lie代数

设A是有限域k上的有限维tame遗传代数,X,Y,M是有限生成A模,如果X,Y不可分解,证明了存在Hall多项式gMXY.设L(A)是以有限生成不可分解模为基的自由Abel群,则L(A)是退化Ringel-Hall代数(A)1的Lie子代数,设L′(A)是L(A)的由单模生成的Lie子代数,m是齐次正则单模的长度,证明了当M不可分解且m不整除M的长度时,［M］∈L′(A).     

Noether模的Artin根

本文定义了Ｎｏｃｔｈｅｒ模的Ａｒｔｉｎ根，给出了Ｎｏｃｔｈｅｒ半局部环上有限生成模的Ａｒｔｉｎ根的刻划．最后，作为Ａｒｔｉｎ根理论的应用，给出了一个关于Ｃｏｈｅｎ－Ｍａｃａｕｌａｙ环的定理及一个模的用ｄｅｐｔｈ和ｋｒｕｌｌ维数表示的公式。     

一般线性李超代数及其超群的无穷小子群的表示

在索特征代数闭域上考虑一般线性李超代数gl(m |n)的限制表示与超群GL(m | n)的有理表示以及它们的关系.主要结果为: (1)对gl(m | n)的不可约限制表示进行分类,其中某些单模恰是Kac-模.类似于复数域情形,给出了Kac-模不可约的充要条件; (2)当m≠n(mod p)以及p≥2h-2(h=max{m,n})时,gl(m | n)的限制投射模可以被提升为有理GL(m | n)-模,并且证明了不可约表示的投射覆盖具有Z-滤过,即滤过中的每个子商同构于"baby Vlerma模";(3)得到了一般线性超群G=GL(m | n)的r阶nobenius核的反转公式,它反映了单Gγ-模的投射覆盖的Z-滤过重数与广义baby Verma模的合成因子效之间的关系.     

k阶几何无穷可分分布族

一个非退化的m维随机向量Y称为是k阶几何无穷可分的，是指对任何0＜p＜1，存在独立同分布的m维随机向量{Ypi,i≥1}使得Y=,其中Np为取正整数随机变量，服从参数为p和k的广义几何分布，且Np与{Ypi,i≥1）独立．本文给出了这类分布的刻划和应用．     

粉末注射成形填充过程的数值模拟

本文将粉末注射成形喂料在薄壁模腔中的流动视为二维流动，以流变学的基本方程为基础，建立了从动量方程、连续方程和热传递方程得到的描述PIM喂料充模二维流动的数学模型。在无滑移边界的条件下，推导了喂料熔体流导率的计算公式和压力场的控制方程，得到的压力场控制方程是一非线性椭圆偏微分方程．从而可用Galerkin方法进行数值求解，使模型的数值求解成为可能，为进一步对粉末注射成形进行计算机模拟和数值分析奠定了数学基础。     

The tame dimension vectors for trees

We consider representations of quivers over an algebraically closed field K. A dimension vector of a quiver is called hypercritical, if there is an m-parameter family of indecomposable representations for the dimension vector with m?2, but every family of representations for all smaller dimension vectors depends on a single parameter. We characterise the hypercritical dimension vectors for trees via their Tits forms and those of their decompositions and present the complete list of the hypercritical dimension vectors.Finally, this leads to a combinatorial classification of the tame dimension vectors for trees which is also given by the Tits forms.     

Rings of invariants for modular representations of elementary abelian <Emphasis Type="Italic">p</Emphasis>-groups

We initiate a study of the rings of invariants of modular representations of elementary abelian p-groups. With a few notable exceptions, the modular representation theory of an elementary abelian p-group is wild. However, for a given dimension, it is possible to parameterise the representations. We describe parameterisations for modular representations of dimension two and of dimension three. We compute the ring of invariants for all two-dimensional representations; these rings are generated by two algebraically independent elements. We compute the ring of invariants of the symmetric square of a two-dimensional representation; these rings are hypersurfaces. We compute the ring of invariants for all three-dimensional representations of rank at most three; these rings are complete intersections with embedding dimension at most five. We conjecture that the ring of invariants for any three-dimensional representation of an elementary abelian p-group is a complete intersection.     

Modular Hadamard martrices and related designs

A square matrix with entries ± 1 is called a modular Hadamard matrix if the inner product of each two distinct row vectors is a multiple of some fixed (positive) integer. This paper initiates the study of modular Hadamard matrices and the combinatorial designs associated with them. The related combinatorial designs are the main concern of this paper; some results dealing with the existence and construction of modular Hadamard matrices will be included in a later paper.     

Fibonacci数列的模数列的周期的一个性质

Fibonacci数列的模数列是周期数列,并且是纯周期数列.利用模数列的定义,讨论了Fibonacci数列的模数列的周期的一个性质,证明了下列结果:假设m1与m2为不同的正整数,Fibonacci数列{Fn}的模数列{an(m1)}与{an(m2)}的最小正周期分别为T1与T2,则模数列{an([m1,m2])}的最小正周期为[T1,T2].     

奇Hamiltonian型滤过李超代数HO

本文应用象空间极小维数的方法研究了Cartan型模李超代数HO的非平凡可迁滤过(HO,R)的不变性.应用滤过的不变性得到模李超代数HO的某些内蕴性质,从而得到此类李超代数在同构意义下的分类.     

STABILITY OF CERTAIN RINGS OF HIGHEST WEIGHT VECTORS

51. IntroductionLet Cm'" be the space of complex m x n matrices, P(Cm)") be the algebra of complexpolynomials on Cd'~. Let GLm(C) x GL.(C) act on P(Cm,") as the following:(gi, gZ)f(x) ~ f(g,'xg,),where x E Cat", (gi, g2) E GLm x GL., f E P(Cm'"). This action induces an action of thesubgroup Of x GL. on P(Cm)") by restriction.Let G be a complex reductive algebraic group, (V, p) be a rational representation of G.Let B = TU be a Borel subgroup of G, where T is a majximal torns of …     

Dimension and automorphism groups of lattices

Every group is the automorphism group of a lattice of order dimension at most 4. We conjecture that the automorphism groups of finite modular lattices of bounded dimension do not represent every finite group. It is shown that ifp is a large prime dividing the order of the automorphism group of a finite modular latticeL then eitherL has high order dimension orM _p, the lattice of height 2 and orderp+2, has a cover-preserving embedding inL. We mention a number of open problems. Presented by C. R. Platt.     

Group-valued modular functions

Modular functions on a lattice (m(x)+m(y)=m(x∪y)+m(x∩y)) live on modular lattices in that they are induced by modular functions on a quotient modular lattice. Those which identify pairs of the distributive inequality live on distributive lattices in the same sense. The structure of all modular functions on a lattice of finite height is determined. The “distance function” derived by Kranz from a modular function is shown to satisfy the triangle inequality. Presented by E. Nelson.     

An modular maximal vectors,I: bases,rank 2 families,and an introduction to products

This is the first in a brief series of articles constructing p—modular maximal vectors in an admissible lattice in a finite dimensional irreducible module of highest weight for a simple lie algebra of type A_n. There will be no limitation on the prime integer p. The constructions themselves will be directly applicable to most other simple types. The ultimate goal is, of course, a modular Weyl formula.     

解一类对称不定线性方程组的奇异方向法

此处B为n×n对称正定矩阵,G是秩为m的n×m矩阵.这是在最优化问题和混合有限元法中大量出现的一类方程组,因此,它的求解问题引起人们的注意. 求解对称不定线性方程组问题已有较多讨论,但针对(2)中A的特殊性构造的算法尚