首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Warsaw圈上映射的等度连续性   总被引:4,自引:0,他引:4  
顾荣宝 《数学研究》2002,35(3):249-256
设W是Warsaw圈:f:W→W是连续映射,本证明f是等度连续映射的充分必要条件是下列两个条件之一成立:(1)F(f)是一个单点集并且F(f^2)=∩^∞n=1f^n(W);(2)F(f)=∩^∞n=1f^n(W)。  相似文献   

2.
在扩大模型下,应用单子理论给出了拓扑等度连续和均匀连续的非标准刻画,并应用均匀连续的非标准特征证明了网收敛与均匀连续之间的关系,最后应用拓扑等度连续和均匀连续的非标准特征证明了拓扑等度连续和均匀连续之间的关系.  相似文献   

3.
给出了Lebesgue积分列的等度绝对连续的一个充分必要条件.  相似文献   

4.
本文引进并研究了Furstenberg族意义下的处处混沌与等度连续的概念.如果一个动力系统是F_1-敏感和F_2-可达的,则称之为(F_1,F_2)-处处混沌的,其中F_1与F_2是Furstenberg族.一个动力系统(X,f)被称为F_1-敏感的,是指存在7>0使得对任意x∈X及x的任意开邻域存在y∈U,有{n∈Z_+:d(f~n(x),f~n(y))>τ}∈F_1成立.一个动力系统(X,f)被称为F_2-可达的,是指对任意的s>O及X的任意非空开集U,V,存在x∈U,y∈V使得{n∈Z_+:d(f~n(x),f~n(y))<ε}∈F_1成立.一个动力系统被称为F-等度连续的,是指对任意的ε>0,存在δ>0,当d(x,y)<δ时有{n∈Z_+:d(f~n(x),f~n(y))<ε}∈F成立,其中F是一个Furstenberg族.  相似文献   

5.
设W为华沙圈,f:W→W为连续映射.本文得到了f为distal的一个刻画并且讨论了f的distality与等度连续性的关系.证明了:(i)f是distal的当且仅当f为恒等映射.(ii)如果f为满射,则f是distal的当且仅当f为等度连续的.  相似文献   

6.
在函数列的收敛性、一致收敛性的基础上,进一步研究函数列的等度连续性.根据函数列的等度连续性定义,证明了等度连续函数列的一些性质,并且讨论了函数列一致性收敛性、等度连续性、一致有界性等特性之间的关系。  相似文献   

7.
等度连续与POTP   总被引:3,自引:0,他引:3  
本文证明了在紧致连通的度量空间中,等度连续的自映射不具有POTP。  相似文献   

8.
树映射的等度连续性   总被引:5,自引:0,他引:5  
孙太祥 《数学研究》2001,34(2):125-130
讨论了树(即:不含圈的维紧致连通的分支流形)映射的等度连续性,得到了树映射是等度连续的两个充要条件。  相似文献   

9.
一个抽象的极小极大定理   总被引:1,自引:1,他引:0  
研究Banach空间中强极小正则锥导出的半序结构,得到一个抽象的极小极大定理.  相似文献   

10.
设X是一个紧致度量空间,f:X→X是一个连续映射,(X,f)是熵极小的.该文首先证明了f是强遍历的;另外,如果还假设X中存在f的一个真的(拟)弱几乎周期点,则得到f具有正拓扑熵且对任意的n1,f~n是遍历敏感依赖的.因此,f在Li-Yorke和Takens-Ruelle意义下是混沌的.该文所得结论改进和推广了最近的一些结论.  相似文献   

11.
V.F. Demyanov introduced exhausters for the study of nonsmooth functions. These are families of convex compact sets that enable one to represent the main part of the increment of a considered function in a neighborhood of the studied point as MaxMin or MinMax of linear functions. Optimality conditions were described in terms of these objects. This provided a way for constructing new algorithms for solving nondifferentiable optimization problems. Exhausters are defined not uniquely. It is obvious that the smaller an exhauster, the less are the computational expenses when working with it. Thus, the problem of reduction of an available family arises. For the first time, this problem was considered by V.A. Roshchina. She proposed conditions for minimality and described some methods of reduction in the case when these conditions are not satisfied. However, it turned out that the exhauster mapping is not continuous in the Hausdorff metrics, which leads to the problems with convergence of numerical methods. To overcome this difficulty, Demyanov proposed the notion of coexhausters. These objects enable one to represent the main part of the increment of the considered function in a neighborhood of the studied point in the form of MaxMin or MinMax of affine functions. One can define a class of functions with the continuous coexhauster mapping. Optimality conditions can be stated in terms of these objects too. But coexhausters are also defined not uniquely. The problem of reduction of coexhausters is considered in this paper for the first time. Definitions of minimality proposed by Roshchina are used. In contrast to ideas proposed in the works of Roshchina, the minimality conditions and the technique of reduction developed in this paper have a clear and transparent geometric interpretation.  相似文献   

12.
IfN is the nilpotent constituent of an Iwasawa decomposition of the semi-simple groupG (finite center and no compact factors), it is proved thatN acts minimally onG/Γ for every uniform lattice Γ ?G, generalizing theorems of Hedlund and L. Greenberg.  相似文献   

13.
Necessary and sufficient conditions are obtained for the incompleteness and the minimality of the exponential system E(Λ,M) = {z l e λ n z : l = 0,1,...,m n-1;n = 1,2,...} in the Banach space E 2 [σ] consisting of some analytic functions in a half strip.If the incompleteness holds,each function in the closure of the linear span of exponential system E(Λ,M) can be extended to an analytic function represented by a Taylor-Dirichlet series.Moreover,by the conformal mapping ζ = φ(z) = e z ,the similar results hold for the incompleteness and the minimality of the power function system F (Λ,M) = {(log ζ) l ζ λ n : l = 0,1,...,m n-1;n = 1,2,...} in the Banach space F 2 [σ] consisting of some analytic functions in a sector.  相似文献   

14.
A sufficient condition is obtained for the minimality of the complex exponential system E(A, M) = {z^le^λnz: l = 0, 1,,.., mn - 1; n = 1, 2,...} in the Banaeh space La^p consisting of all functions f such that f^-a ∈ LP(N). Moreover, if the incompleteness holds, each function in the closure of the linear span of exponential system E(A, M) can be extended to an analytic function represented by a Taylor-Dirichlet series.  相似文献   

15.
16.
本文提出一种同时估计个体报告真实回答的概率T和敏感指标均值μ_x的无关问题模型,文中讨论了T和μ_x估计量的性质以及样本容量的匹配.本文计算了所提出方法与直接调查方法的相对效率,结论表明,存在不真实回答情况下,本文提出方法可以比直接调查更有效.  相似文献   

17.
We give a complete classification of the locally finite groups that are minimal with respect to Sylow-permutability being intransitive.  相似文献   

18.
得到了随机指数系在加权Banach空间C_α中完备和极小的充要条件,其中C_α是实直线R上的复连续函数在权α的一致范数下组成的Banach空间.这些结果可以看作是Malliavin经典结果的概率推广.  相似文献   

19.
得到了随机指数系在加权Banach空间Cα中完备和极小的充要条件,其中Cα是实直线R上的复连续函数在权α的一致范数下组成的Banach空间.这些结果可以看作是Malliavin经典结果的概率推广.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号