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1.
本文研究了Banach空间的弱序列紧性.Banach空间X称为有(w)性质,如果X(X的共轭空间)的每个有界序列有弱收敛子列.我们证明了,如果Banach空间X有(w)性质,那么lp(X)(1≤p<+∞)与c0(X)也有(w)性质.  相似文献   

2.
本文引入了Banacj空间X的弱局部Z性质和弱Z性质,得出了:Banach空间X是K-NUC空间的一个充分必要条件和Banach空间X是LK-NUC空间的一个充分条件,并指出弱Z性质蕴含弱Banach-Saks性质.  相似文献   

3.
本文引入了Banacj空间X的弱局部Zk性质和弱Zk性质,得出了:Banach空间X是K-NUC空间的一个充分必要条件和Banach空间X是LK-NUC空间的一个充分条件,并指出弱Zk性质蕴含弱Banach-Saks性质.  相似文献   

4.
本文定义了Banach空间值的随机测度的弱*收敛的概念,并表征了Banach空间值的对称独立散射随机测度的弱*收敛性.另一方面,证明了,关于Banach空间值的对称独立散射随机测度在较弱意义下的结果,即弱收敛推得弱*收敛.  相似文献   

5.
一类弱稳定的Banach空间   总被引:1,自引:1,他引:0  
为了解决什么样的Banach空间,它的每个无穷维子空间几乎等距地含有C0或lp(1≤p<∞)问题,J.L.Krivine1979年在[4]中引进了稳定的Banach空间的概念.S.Argyors.在[2]中引进了弱稳定的概念,列举了一个弱稳定而非稳定的Banach空间,本文引进具有P-凸完备极小系的Banach空间,证明了该空间是弱稳定以及可赋等价的稳定范数的充要条件是其自反.最后给出了不自反的具有P—凸完备极小系的Banach空间的例子从而推广了[2]中结果.  相似文献   

6.
Banach空间的K—M逼近   总被引:1,自引:0,他引:1  
崔云安 《应用数学》1995,8(4):409-413
设X是自反、严格凸且具有H性质的Banach空间,A是X的弱序列完备子集。本文证明了A是可逼近紧的Chebyshev集的充分必要条件是A是太阳集;同时,也讨论了Orlicz序列空间的太阳集。  相似文献   

7.
设X 为Banach 空间,B(X)为X 上有界线性算子全体组成的代数,本文给出了B(X)上保k 次幂弱连续线性满射的完全刻划.  相似文献   

8.
本文中我们给出了置换空间PXXn中(弱)Hahn-Banach光滑性提升性质,它们是lp(Xn)中相应结果的推广(1<p<∞).  相似文献   

9.
甘师信 《数学杂志》1994,14(3):387-395
本文证明了Banach空间值鞅的一些不等式,讨论了Banach空间的凸性及光滑性与某些鞅不等的式的联系,给出了Hilbert空间的一个鞅不等式刻划,同时还讨论了一致P光滑空间中鞅的弱大数定律,本文的结论推广与改进了很多熟知的定理。  相似文献   

10.
倪仁兴  李冲 《数学学报》2000,43(3):421-426
本文研究Banach空间X中远达和同时远达问题的适定性,在集合的Haus- dorff距离下,对X中的闭凸子集D和相对弱紧的有界闭子集K,证明了下述结果: 若D关于K严格凸和有Kadec性质,则D中所有使远达问题 max{x,K}是适定的 点x全体在D中是Gδ型集.作为应用,得到了同时远达问题适定性的类似结果.  相似文献   

11.
本文就可分Banach空间中元素的最小序列(也称双直交序列)可以扩充到在全空间中完备这一事实,说明在空间不可分情况下,对于由不可数个元素组成的所谓最小系,这种完备性扩充未必可行.此外,还应用最小序列扩充性质给出可分的遗传不可分解空间的一个特征刻画.  相似文献   

12.
Functional Analysis and Its Applications - We consider Borel measures on separable Banach spaces that are limits of their finite-dimensional images in the weak topology. The class of Banach spaces...  相似文献   

13.
Cylindrical Wiener processes in real separable Banach spaces are defined, and an approximation theorem involving scalar Wiener processes is given for such processes. A weak stochastic integral for Banach spaces involving a cylindrical Wiener process as integrator and an operator-valued stochastic process as integrand is defined. Basic properties of this integral are stated and proved.A class of linear, time-invariant, stochastic differential equations in real, separable, reflexive Banach spaces is formulated in such fashion that a solution of the equation is a cylindrical process. An existence and uniqueness theorem is proved. A stochastic version of the problem of heat conduction in a ring provides an example.Research supported by National Science Foundation under Grant No. ECS-8005960.  相似文献   

14.
We prove a mean-value theorem for lower semicontinuous functions on a large class of Banach spaces which contains the class of Asplund spaces, in particular reflexive Banach spaces and Banach spaces with a separable dual. It involves the lower subdifferential (or contingent subdifferential) and the Fréchet subdifferentials, which are among the smallest subdifferentials known to date. It follows that the estimates which it provides require weak assumptions and are accurate. When the function is locally Lipschitzian, we get a simple statement which refines the Lebourg mean-value theorem.  相似文献   

15.
We will introduce the countable separation property (CSP) of Banach spaces X, which is defined as follows: X has CSP if each family E of closed linear subspaces of X whose intersection is the zero space contains a countable subfamily E0 with the same intersection. All separable Banach spaces have CSP and plenty of examples of non-separable CSP spaces are provided. Connections of CSP with Marku?evi?-bases, Corson property and related geometric issues are discussed.  相似文献   

16.
Abstract

We consider random set-valued measures with values in a separable Banach space. We prove two integral representation theorems using measurable multifunctions and set-valued integrals. The first theorem is valid for all separable Banach spaces, while the second holds for reflexive separable Banach spaces.  相似文献   

17.
We study the stability properties of the class of weak*-extensible spaces introduced by Wang, Zhao, and Qiang showing, among other things, that weak*-extensibility is equivalent to having a weak*-sequentially continuous dual ball (in short, w*SC) for duals of separable spaces or twisted sums of w*SC spaces. This shows that weak*-extensibility is not a 33-space property, solving a question posed by Wang, Zhao, and Qiang. We also introduce a restricted form of weak*-extensibility, called separable weak*-extensibility, and show that separably weak*-extensible Banach spaces have the Gelfand–Phillips property, although they are not necessarily w*SC spaces.  相似文献   

18.
ONTHECENTRALLIMITTHEOREMINPRODUCTSPACESSUZHONGGENAbstract:SupposethatEandFareseparableBanachspaces,XandYareindependentsymmetr...  相似文献   

19.
本文研究取值在Banach空间中的随机变量序列的强收敛问题,在假设随机变量序列弱大数定律成立的条件下,证明了一般形式的Teicher强大数定律成立.  相似文献   

20.
Norming subspaces are studied widely in the duality theory of Banach spaces. These subspaces are applied to the Borel and Baire classifications of the inverse operators. The main result of this article asserts that the dual of a Banach space X contains a norming subspace isomorphic to 1 provided that the following two conditions are satisfied:(1) X*contains a subspace isomorphic to 1;and(2) X*contains a separable norming subspace.  相似文献   

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