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1.
沈斌  康琳 《中国科学:数学》2011,41(8):689-699
本文证明了非Riemannian (α, β)- 空间中的Killing 向量场最大维数是n(n - 1)/2 + 1. 并且给出了具有最大维数Killing 向量场的非Riemannian (α, β)- 空间的度量形式. 最后, 若进一步假定α 是一个齐性Riemannian 度量, 则可确定(α, β)- 空间的第二空隙. 最后给出几个低维流形上Killing 场空间维数的例子, 这表明在(α, β) 情形下Killing 场空间维数的空隙被压缩.  相似文献   

2.
黄兆泳 《中国科学A辑》2000,30(9):808-816
引进了相对于一个双模 ω-的ω-k-挠自由模,用左addR ω-逼近刻画了ω-k-挠自由模.引进了 ω-左逼近维数,描述了是k-挠自由模的k-合冲模的形式.  相似文献   

3.
一类二次保形拟插值函数的研究   总被引:1,自引:0,他引:1  
通过讨论一种保形拟插值的基函数与二次规范B-样条函数之间的关系,提出了一类二次保形拟插值样条函数,得到了这类保形拟插值函数在具有线性再生性质,并保持原有数据点列的单调性和凸性时分别应满足的条件,并给出几个应用实例.  相似文献   

4.
伪内射模与主伪内射模   总被引:1,自引:0,他引:1       下载免费PDF全文
本文研究了伪内射模与主伪内射模,它们分别是拟内射模与PQ-内射模的推广.伪内射模是对偶于伪投射模的.我们讨论了伪内射模与主伪内射模的性质及其自同态环,并得到了自同态环的Jacobson根的若干性质.  相似文献   

5.
本文研究p-adic 域Qp 上的一类拟微分算子{Tα : α∈R}, 其中算子Tα 在Qp 的检验函数空 间S(Qp) 以及相应的分布空间S′(Qp) 中作为一个运算是封闭的. 本文构造了算子Tα 的卷积核, 指 出算子与其卷积核在解决p-adic 域上的相关问题中所起的重要作用. 最后研究算子Tα 的谱性质, 构 造了算子Tα 的全体固有值与固有函数, 并证明全体固有函数所成的集合组成L2(Qp) 空间中的一组 完整正交基.  相似文献   

6.
本文给出了关于L0- 线性函数的Hahn-Banach 扩张定理的几何形式并证明这个几何形式等价于它的代数形式. 进一步, 我们利用这个几何形式给出了随机局部凸模中熟知的基本分离定理的一个新的且简单的证明. 最后, 利用这个分离定理, 我们同时在两种拓扑 —(ε, λ)- 拓扑和局部L0- 凸拓扑下证明了随机赋范模中的Goldstine-Weston 稠密性定理, 并举出一个反例说明在局部L0- 凸拓扑下如果随机赋范模不具有可数连接性质, 则Goldstine-Weston 稠密性定理不一定成立.  相似文献   

7.
多元弱样条空间和最小确定集   总被引:1,自引:1,他引:0  
根据研究多元弱样条函数的B—网方法,给出了某些多元弱样条函数空间的最小确定集的构造方法,并从而求出了它们的维数.本文还讨论了对偶基的局部支集性质。  相似文献   

8.
首先给出了三角样条函数及其性质,然后在此基础上给出了一种构造三角样条小波的新方法.该方法简单易行,而且构造出的小波具有许多良好的性质,如对称性(具有线性相位或广义线性相位)、良好的时频局部特性、短支集及半正交性等,这些对信号处理是非常重要的.  相似文献   

9.
本文根据Cowen-Douglas 算子的定义引入两类与强不可约算子有紧密联系的算子类— Bn 算子与B 算子. 说明了在可分Banach 空间上存在Bn 算子与B 算子. 文章详细讨论了几种具有不可约性的算子类之间的关系并得到了一个关系图. 本文还给出这些算子类的一些性质, 包括算子的(拟) 相似不变性等.  相似文献   

10.
朱春钢 《应用数学》2006,19(3):575-579
二元样条函数插值在计算几何与计算机辅助几何设计中有着重要的作用.本文给出了一种矩形剖分上二元线性样条函数进行Lagrange插值时插值适定结点组所满足的拓扑与几何性质,这种性质依赖于二元线性样条函数所决定的分片线性代数曲线.  相似文献   

11.
Dual pseudo splines constitute a new class of refinable functions with B-splines as special examples.In this paper,we shall construct Riesz wavelet associated with dual pseudo splines.Furthermore,we use dual pseudo splines to construct tight frame systems with desired approximation order by applying the unitary extension principle.  相似文献   

12.
If on the semiaxis [0, + ∞) a continuous positive function ω does not decrease and ω(t)/t does not increase, then the space λ(n) ω(n≥1) has only standard ideals. For n =0 one has to require for this that ω(t)=0(tα) for some number α, α >0.  相似文献   

13.
In this work, we prove the existence and uniqueness of μ-pseudo almost periodic and μ-pseudo almost automorphic solutions in the α ?norm for some classes of partial differential equations in Banach spaces. For illustration, we study some models arising in physical systems.  相似文献   

14.
In this paper, we introduce complex pseudo splines that are derived from pseudo splines of type I. First, we show that the shifts of every complex pseudo spline are linearly independent. Therefore we can construct a biorthogonal wavelet system. Next, we investigate the Riesz basis property of the corresponding wavelet system generated by complex pseudo splines. The regularity of the complex pseudo splines will be analyzed. Furthermore, by using complex pseudo splines, we will construct symmetric or antisymmetric complex tight framelets with desired approximation order.  相似文献   

15.
Recently, Behforooz [1], has introduced a new approach to construct cubic splines by using the integral values, rather than the usual function values at the knots. Also he has established different sets of end conditions for cubic and quintic splines by using the integral values, see Behforooz [2], [3] and [4]. In this paper, we will use the same techniques of [1] to construct integro quintic splines. Although by using the integral values we expected to face a more complicated process for our construction, it turned out that the matrix of the system of linear equations that produces the parameters became a diagonally dominant matrix and the process became very simple. The selection of the required end conditions for our integro quintic splines will be discussed. The numerical examples and computational results illustrate and guarantee a higher accuracy for this approximation.  相似文献   

16.
In this paper we discuss the existence and global attractivity of k-pseudo almost automorphic sequence solution of a model of bidirectional cellular neural networks. We consider the corresponding difference equation analogue of the model system using suitable discretization method and obtain certain conditions for the existence of solution. The k-pseudo almost automorphic sequence solutions generalize the results of pseudo almost periodic, almost periodic and almost automorphic sequences solutions. Moreover the results proved in this paper are new and compliment the existing one.  相似文献   

17.
In this paper we present an approximation method of surfaces by a new type of splines, which we call fairness bicubic splines, from a given Lagrangian data set. An approximating problem of surface is obtained by minimizing a quadratic functional in a parametric space of bicubic splines. The existence and uniqueness of this problem are shown as long as a convergence result of the method is established. We analyze some numerical and graphical examples in order to prove the validity of our method.  相似文献   

18.
In this work, we establish a new concept of pseudo almost periodic processes in p-th mean sense using the measure theory. We use the μ-ergodic process to define the spaces of μ-pseudo almost periodic process in the p-th mean sense. We establish many interesting results on the functional space of such processes like completeness and composition theorems. The main objective of this paper is to use those results and some stochastic analysis approaches to study the existence, the uniqueness and the global attractiveness for a μ-pseudo almost periodic mild solution to a class of abstract stochastic evolution equations driven by fractional Brownian motion. We provide an example to illustrate our results.  相似文献   

19.
本文提出了一些新概念,p—伪转置阵,p—伪正交阵,p—伪对称阵,从而能以这些矩阵为工具研究伪欧氏空间的性质以及空间中两个特殊线性变换,伪正交变换和伪对称变换.本文得到的主要结果是定理2,定理3,定理4及定理6.本文还指出了北大编《高等代数》第二版中的伪正交变换习题的一个错误.  相似文献   

20.
In this work, we consider a class of neutral shunting inhibitory cellular neural networks with mixed delays. We study the existence, uniqueness, and the exponential stability of the measure pseudo almost periodic (or μ-pseudo almost periodic) solutions from some models for shunting inhibitory cellular neural networks with mixed delays. An example is provided to illustrate the theory developed in this work.  相似文献   

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