Hardy型空间HKP（R^n）的实变特征

作者对Ｈａｒｄｙ型空间ＨＫＰ（Ｒ＾ｎ）建立了相应于Ｈ＾１（Ｒ＾ｎ）的各种实变特征，并且考虑了ＨＫＰ（Ｒ＾ｎ）的加权空间，此外，作者还证明了两类奇异积分算子的ＨＫＰ（Ｒ＾ｎ）－有界性，而它们在Ｈ＾１（Ｒ＾ｎ）上是无界的。     

E^n空间中Finsler—Hadwiger不等式的k维对偶式

本文首先给出一个代数不等式,其次利用它获得了ｎ维欧氏空间Ｅ＾ｎ中联系任意ｍ个单形的ｋ维与ｎ维体积的一个几何不等式,作为其特殊情况得到了Ｆｉｎｓｌｅｒ－Ｈａｄｗｉｇｅｒ不等式在Ｅ＾ｎ中的Ｋ维对偶式。     

关于类空W超曲面的一个存在性定理

利用超曲面的旋转对称性，将ＰＤＥ的求解转化为ＯＤＥ的求解，确定了Ｄｅ Ｓｉｔｔｅｒ空间中的一类旋转型的Ｗｅｉｎｇａｒｔｅｎ超曲面。即获得：给定Ｒ＾ｎ－１内开集（０，∞）＾ｎ－１上一个Ｃ＾１函数ｋｎ＝ｆ（ｋ１，…，ｋｎ－１）（ｎ≥２），一定存在Ｄｅ Ｓｉｔｔｅｒ空间Ｓ１＾ｎ＋１内的ｎ维类空旋转超曲面Ｍ，使得Ｍ的ｎ个主曲率ｋ１，…，ｋｎ恰有上述函数关系。     

关于广义导算子的零空间

本文讨论了两类广义导算子δＡＢ（ｘ）＝Ａｘ－ｘＢ和τＡＢ（ｘ）＝ＡｘＢ－ｘ，并给出了一些Ｋｅｒδ＾（ｎ）ＡＢ，Ｋｅｒτ＾ｎＡＢ＝ＫｅｒτＡＢ成立的充分必要条件。     

向量的夹角概念在高维欧氏空间E^n中的推广

本文给出了Ｅ＾ｎ中不同维数平面之间多维角、单维角的定义，它们是向量的夹角概念的推广其几何意义非常明显，在此基础上还给出了ＱＡＢＰ＾－１Ａ的特征多项式各项系数的几何意义，这些结论对于研究各类曲率非常有用。     

弱Herz空间的应用

设１〈ｑ〈∞和０〈ｐ≤１，本文证明了一大类算子有界地映Ｈｅｒｚ空间Ｋｑ＾ｎ（１－１／ｑ，＾ｐ（Ｒ＾ｎ）到弱Ｈｅｒｚ空间ＷＫｑ＾ｎ（１－１／ｑ），＾ｐ（Ｒ＾ｎ）。本文还引入了弱Ｈｅｒｚ型Ｈａｒｄｙ空间，并且证明了局部Ｃａｌｄｅｒｏｎ－Ｚｙｇｍｕｎｄ型算子有界地映Ｈｅｒｚ型Ｈａｒｄｙ空间到弱Ｈｅｒｚ型Ｈａｒｄｙ空间。     

稳定随机游动二重时集的离散Hausdorff维数

设（Ｘ）ｎ≥０是ｄ维格子点上相应于正则变差函数ｂ（ｎ）＝ｎ＾１／βＳ（ｎ）的稳定随机游动，称为（Ｘｎ）ｎ≥０的二重时集，时文讨论了Ａ＾ｄβ的离散Ｈａｕｓｄｏｆｒｒ维数，并且在较弱的条件下证明了：ｄｉｍＨ（Ａ＾ｄβ）（１当ｄ＞β时，２－ｄ／β当ｄ≤β时     

关于R^n中Moebius变换群的代数有限性

本文推广了Ｅｉｃｈｌｅｒ在Ｋｌｅｉｎ群的研究中所采用的上同调方法，对于Ｒ＾ｎ中的Ｍｏｅｂｉｕｓ变换群引进更为一般的线性上同调空间的概念。在此基础上，将作者早期的工作加以推广，研究Ｒ＾ｎ中Ｍｏｅｂｉｕｓ变换群的代数有限性，并作为特例给出高维Ｋｌｅｉｎ群有限性的一种代数判据。     

关于代数体函数的Nevanlinna第二基本定理

设（Ａ，（ｚ））＾ｎｉ＝０为复平面上的整函数且没肥公共零点，令ｋ＋１是（Ａｉ（ｚ））＾ｎｉ＝０在复数域上的极大线性无关数，设Ｗ＝Ｗ（ｚ）由下列不可约方程Ａｎ（ｚ）Ｗ＾ｎ＋Ａｎ－１（ｚ）Ｗ＾ｎ－１＋．．．＋Ａ１（ｚ）ｗ＋Ａ０（ｚ）＝０所定义，我们称Ｗ＝Ｗ（Ｚ）为ｎ值ｋ型代数体函数（１≤Ｋ≤ｎ）。     

R~n和RP~n上的多项式系统

本文讨论了ｎ维欧氏空间Ｒｎ（ｎ＞２）上的多项式向量场集合的系数拓扑不变量，可分为具有不同全局拓扑性质的两类不交的子集合；证明了Ｒｎ上的多项式向量场可连续地延拓成ｎ维射影空间ＲＰｎ上的连续多项式向量场的充要条件，反应了其次数与系数相关的拓扑性质；还证明了平面上的多项式向量场的赤道是闭轨线和不变集的充要条件．     

Abel群的一些分解定理的推广(Ⅲ)

从主理想整环上有界模分解的Prüfer-Baer定理出发,研究(无限维)向量空间的代数的线性变换的几个基本问题,得到了如下结果:设V是域F上的(无限维)向量空间,A是V上的一个代数的线性变换,则有(1)若任何与A可交换的线性变换均与线性变换B可交换,则B=f(A),其中f是F上的多项式.进而线性变换B也是代数的.(2) V中存在一组基,使A在这组基下的矩阵是有理标准型(经典标准型)矩阵.当F是代数闭域时,经典标准型矩阵即为若当标准型矩阵.(3)当F是代数闭域时,A存在相应的Jordan-Chevalley分解.进一步,该结论在完全域上仍成立.这些研究推广了有限维向量空间上线性变换的相关结果.     

Separable polynomials over finite dimensional algebras

In [5] it was shown that for a polynomial P of precise degree n with coefficients in an arbitrary m-ary algebra of dimension d as a vector space over an algebraically closed fields, the zeros of P together with the homogeneous zeros of the dominant part of P form a set of cardinality n^d or the cardinality of the base field. We investigate polynomials with coefficients in a d dimensional algebra A without assuming the base field k to be algebraically closed. Separable polynomials are defined to be those which have exactly n^d distinct zeros in [Ktilde] ?_k A [Ktilde] where [Ktilde] denotes an algebraic closure of k. The main result states that given a separable polynomial of degree n, the field extension L of minimal degree over k for which L ?_k A contains all nd zeros is finite Galois over k. It is shown that there is a non empty Zariski open subset in the affine space of all d-dimensional k algebras whose elements A have the following property: In the affine space of polynomials of precise degree n with coefficients in A there is a non empty Zariski open subset consisting of separable polynomials; in other polynomials with coefficients in a finite dimensional algebra are “generically” separable.     

Frames for vector spaces and affine spaces

A finite frame for a finite dimensional Hilbert space is simply a spanning sequence. We show that the linear functionals given by the dual frame vectors do not depend on the inner product, and thus it is possible to extend the frame expansion (and other elements of frame theory) to any finite spanning sequence for a vector space. The corresponding coordinate functionals generalise the dual basis (the case when the vectors are linearly independent), and are characterised by the fact that the associated Gramian matrix is an orthogonal projection. Existing generalisations of the frame expansion to Banach spaces involve an analogue of the frame bounds and frame operator.The potential applications of our results are considerable. Whenever there is a natural spanning set for a vector space, computations can be done directly with it, in an efficient and stable way. We illustrate this with a diverse range of examples, including multivariate spline spaces, generalised barycentric coordinates, and vector spaces over the rationals, such as the cyclotomic fields.     

Conditions on decomposable symmetric tensors as an algebraic variety

Let V be a finite dimensional vector space of dimension at least 2 over an infinite field F. We show that the set of all decomposable elements in the rth symmetric product space over i:V(r≥ 2) is an algebraic set if F is algebraically closed and only if every polynomial of degree at most r splits completcly over F.     

一类子空间格

令Ｖ_n（ｑ）是具ｑ个元素的有限域上的ｎ维向量空间．Ｃ［ｎ,ｋ］是Ｖ_n（ｑ）中与某ｋ维子空间相交不为零空间之子空间全体按包含关系所成偏序集,Ｗ_m为其Ｗｈｉｔｎｅｙ数（０≤ｍ≤ｎ）．本文证明了Ｃ［ｎ,ｋ］具Ｓｐｅｒｎｅｒ性质和单峰性质．进一步地,W_m²-qW_m-1W_m+1作为ｑ的多项式具有非负系数,并且W₀≤W_n≤W₁≤W_n-1≤W₂≤…．     

Strong duality and sensitivity analysis in semi-infinite linear programming

Finite-dimensional linear programs satisfy strong duality (SD) and have the “dual pricing” (DP) property. The DP property ensures that, given a sufficiently small perturbation of the right-hand-side vector, there exists a dual solution that correctly “prices” the perturbation by computing the exact change in the optimal objective function value. These properties may fail in semi-infinite linear programming where the constraint vector space is infinite dimensional. Unlike the finite-dimensional case, in semi-infinite linear programs the constraint vector space is a modeling choice. We show that, for a sufficiently restricted vector space, both SD and DP always hold, at the cost of restricting the perturbations to that space. The main goal of the paper is to extend this restricted space to the largest possible constraint space where SD and DP hold. Once SD or DP fail for a given constraint space, then these conditions fail for all larger constraint spaces. We give sufficient conditions for when SD and DP hold in an extended constraint space. Our results require the use of linear functionals that are singular or purely finitely additive and thus not representable as finite support vectors. We use the extension of the Fourier–Motzkin elimination procedure to semi-infinite linear systems to understand these linear functionals.     

Clifford Algebras of Forms of Higher Degrees

The aim of this lecture is to introduce Clifford algebras of polynomial forms of higher degrees. We recall that these algebras are in general of infinite dimension, and we give a basis depending on a given basis of the underlying vector space. We then show that, though they contain large free associative algebras, we may construct finite dimensional representations of these algebras, also called linearizations of the polynomial form. If the polynomial form is, in a certain sense, non degenerate, the dimensions of these representations are multiples of the degree of the form. In the end, we recall some results known for the special case of a binary cubic form with at least one simple zero, when explicit computations can be done: the Clifford algebra is an Azumaya algebra of rank 9 over its center, which is the algebra of functions over a cubic curve depending on the given cubic form.     

Conditions on decomposable symmetric tensors as an algebraic variety

Let V be a finite dimensional vector space of dimension at least 2 over an infinite field F. We show that the set of all decomposable elements in the rth symmetric product space over i:V(r≥ 2) is an algebraic set if F is algebraically closed and only if every polynomial of degree at most r splits completcly over F.     

二元叠加码M_q(n,k,d)码的平均汉明距离和均方差

根据二元叠加码(Binary Superimposed Code)M_q(n,k,d)的定义及有限域F_q上n维向量空间的k维子空间的维数性质定义了一个高斯组合函数,利用这个组合函数研究了M_q(n,k,d)码的平均汉明(Hamming)距离和它的均方差问题,给出了计算公式.