共查询到20条相似文献,搜索用时 676 毫秒
1.
关于Banach空间的遗传不能分解和商遗传不能合成性质 总被引:4,自引:0,他引:4
钟怀杰 《数学物理学报(A辑)》1997,17(3):274-279
该文说明遗传不能分解空间上的黎斯算子类构成了最大、非平凡的算子理想,简化了Gowers和Maurey关于这类空间上算子构成的推证.应用对偶原理,引入商遗传不能合成的概念,讨论商遗传不能合成的Banach空间上的算子构成,得到了相应的一些结果. 相似文献
2.
关于G-M成果研究的若干新动态Ⅱ--与G-M型空间相关的算子 总被引:2,自引:0,他引:2
结合自己的工作,对Gowers-Maurey系列成果获Fields奖以来的研究的新动态作一综述,该是下篇,主要讨论与G-M型空间相关的算子,包括可通过G-M型空间分解的算子,G-M型空间上的算子理想与算子构成,G-M型空间上的算子谱理论等。 相似文献
3.
4.
5.
本文主要讨论超sober空间的一些基本性质,对三类特殊空间的超sober性进行了讨论,并对T0空间X的超sober性与其Smyth幂空间、Hoare幂空间的超sober性之间的关系进行了讨论;用反例说明了可数无限多个超sober空间的乘积一般不是超sober的;证明了若T0空间X不是超sober的,则其超sober化不存在。 相似文献
6.
拓扑空间X称为定向闭包空间(简称DC空间),若它是T0的,且其任一既约闭集都是某定向子集的闭包,此处X赋予特殊化序。本文讨论了定向闭包空间的一些基本性质,证明了偏序集赋予Alexandroof拓扑所得空间和其Smyth幂空间都是DC空间;偏序集赋予上拓扑是quasisober空间当且仅当它是DC空间;DC性对开子空间遗传,但对饱和子空间一般不遗传;对T0空间X,其Smyth幂空间是DC空间一般不蕴含X是DC空间。 相似文献
7.
Banach空间的无穷维子空间结构的若干问题 总被引:1,自引:0,他引:1
赵俊峰 《数学物理学报(A辑)》1994,14(2):190-198
本文论述了关于Banach空间的无穷维子空间结构的两分枝问题,三分枝问题和无条件基序列的存在性等五个问题,这些是当前Banach空间理论中尚未解决的几个基本问题,同时介绍了试图解决这几个问题的有关概念和方法如Banach空间的稳定性,扭曲范数和空间的饱合性等。 相似文献
8.
本文对GB型空间进行了若干讨论,得到了一些结果。 设X为Banach空间,X为X的共轭空间,B(X,X)为X到X的所有有界线性算子组成的空间。如果X中的弱收敛序列为弱收敛序列,则称X为GB型空间。Grothendieck.A于1953年证明了l~∞是GB型空间。显然自反空间是GB型空间。 相似文献
9.
关于S(n)—θ—闭空间 总被引:1,自引:0,他引:1
Dikranjan与Giuli引入了θ^n-闭包算子,定义了S(n),S(n)-闭和S(n)-θ-闭空间,建立了S(n)-θ-闭空间理论,并提出了6个公开问题,本文将从S(n)-θ-空间的极小性和乘积性来介绍S(n)-θ-闭空间理论的最新进展,文中的三个拓扑反例否定回答了Dikranjan与Giuli提出的4个公开问题。 相似文献
10.
证明了正则空间X具有σ遗传闭包保持双网当且仅当或X是cosmic空间,或X是σ闭离散空间,回答了[1]提出的一个问题. 相似文献
11.
Bin Zhao 《高校应用数学学报(英文版)》2009,24(2):237-244
In this paper, the hereditarily almost expandability of inverse limits is investigated, with two results obtained. Let X be the inverse limit space of an inverse system (Xα, π^αβ, ∧}. (1) Suppose X is hereditarily κ-metacompact, if each Xα is hereditarily pointwise collectionwise normal (almost θ-expandable, almost discrete θ-expandable), then so is X; (2) Suppose X is hereditarily κ-σ-metacompact, if each Xα is hereditarily almost σ-expandable (almost discrete σ-expandable = σ-pointwise collectionwise normal), then so is X. 相似文献
12.
Warren B. Moors 《Proceedings of the American Mathematical Society》2006,134(7):2161-2163
In this paper we prove that the product of a Baire space with a metrizable hereditarily Baire space is again a Baire space. This answers a recent question of J. Chaber and R. Pol.
13.
ZHONG Huaijie CHEN Dongxiao CHEN Jianlan Department of Mathematics Fujian Normal University Fuzhou China 《中国科学A辑(英文版)》2004,47(3):372-392
By providing several new varieties of G-M-type Banach spaces according todecomposable and compoundable properties, this paper discusses the operator structuresof these spaces and the K-theory of the algebra of the operators on these G-M-type Ba-nach spaces through calculation of the K-groups of the operator ideals contained in theclass of Riesz operators. 相似文献
14.
A small Dowker space in ZFC 总被引:1,自引:0,他引:1
Zoltan T. Balogh 《Proceedings of the American Mathematical Society》1996,124(8):2555-2560
We construct a hereditarily normal topological space whose product with the unit interval is not normal. The space is -relatively discrete and has cardinality of the continuum .
15.
Suppose that X, Y are two real Banach Spaces. We know that for a standard ε-isometry f : X → Y, the weak stability formula holds and by applying the formula we can induce a closed subspace N of *. In this paper, by using again the weak stability formula, we further show a sufficient and necessary condition for a standard ε-isometry to be stable in assuming that N is w*-closed in Y*.Making use of this result, we improve several known results including Figiel's theorem in reflexive spaces.We also prove that if, in addition, the space Y is quasi-reflexive and hereditarily indecomposable, then L(f)≡span[f(X)] contains a complemented linear isometric copy of X; Moreover, if X =Y, then for every e-isometry f: X → X, there exists a surjective linear isometry S:X → X such that f-S is uniformly bounded by 2ε on X. 相似文献
16.
On Hereditarily Indecomposable Banach Spaces 总被引:1,自引:0,他引:1
Li Xin CHENG Huai Jie ZHONG 《数学学报(英文版)》2006,22(3):751-756
This paper shows that every non-separable hereditarily indecomposable Banach space admits an equivalent strictly convex norm, but its bi-dual can never have such a one; consequently, every non-separable hereditarily indecomposable Banach space has no equivalent locally uniformly convex norm. 相似文献
17.
Teresa Bermú dez Antonio Bonilla Antonio Martinó n 《Proceedings of the American Mathematical Society》2003,131(8):2435-2441
We prove that every separable infinite dimensional complex Banach space admits a hypercyclic uniformly continuous semigroup. We also prove that there exist Banach spaces admitting no chaotic strongly continuous semigroups.
18.
19.
In this paper we first discuss the relations between some G-M-type spaces, and the previous eight kinds of G-M-type Banach spaces are merged into four different kinds. Then we build a Generalized Operator Extension Theorem, and introduce the concept of complete minimal sequences. Some sufficient and necessary conditions under which a Banach space is a hereditarily indecomposable space are given. Finally, we give some characterizations of hereditarily indecomposable Banach Spaces. 相似文献
20.
Let {X i , π k i , ω} be an inverse sequence and $X = \mathop {\lim }\limits_ \leftarrow \left\{ {X_i ,\pi _k^i ,\omega } \right\}$ . If each X i is hereditarily (resp. metaLindelöf, σ-metaLindelöf, σ-orthocompact, weakly suborthocompact, δθ-refinable, weakly θ-refinable, weakly δθ-refinable), then so is X. 相似文献