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.
关于Banach空间算子的本性谱   总被引:1,自引:0,他引:1  
钟怀杰 《数学杂志》1990,10(4):381-384
这篇注记把文献[1]中关于希尔伯特空间算子本性谱特征刻划的某些结果推广到一般巴拿赫空间上去。其中之一是说明,零属于算子 T 的左本性谱的充分必要条件是存在一个紧算子 K,使得 T+K 的零空间无限维,或 R(T)不可补。  相似文献   

2.
苏维钢 《东北数学》2006,22(2):233-240
This paper discusses the special properties of the spectrum of linear operators (in particular, bounded linear operators) on quotient indecomposable Banach spaces; shows that in such spaces generators of Co-groups are always bounded linear operators, and that generators of Co-semigroups satisfy the spectral mapping theorem; and gives an example to show that the generators of Co-semigroups in quotient indecomposable spaces are not necessarily bounded.  相似文献   

3.
孙传崑 《数学杂志》1993,13(1):88-94
对于 Zemanek[3]所提出的如何把本性最小模的概念推广到 Banach 空间中的算子上去的问题,本文从实例(§2)和一般条件(§3)两个方面作了些探讨。  相似文献   

4.
证明了 :在自反 Banach空间$X$中 ,每个闭子空间 L,都存在 X到 L上的拟线性投影算子 SL.一般说来 ,SL 既非度量投影算子 ,又非线性算子 .  相似文献   

5.
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   

6.
刘明学  刘培德 《数学学报》2007,50(2):277-280
证明了一类次可分解算子的不变子空间格是丰富的,并举例说明存在Hilbert空间上的有界线性算子T,它有无穷多个不变子空间,但是它的不变子空间格Lat(T)不丰富.  相似文献   

7.
刘明学 《中国科学A辑》2003,33(2):136-141
利用S. Brown技巧,在稍微增加了一点谱的厚度的情形下证明了Mohebi-Radjabalipour猜想,得到了序列次可分解算子的两个不变子空间定理. 作为特殊情形该结果包含了H. Mohebi 和 M. Radjabalipour得到的一个重要的不变子空间定理.  相似文献   

8.
9.
设E为实光滑、一致凸Banach空间,E*为其对偶空间,TE×E*为极大单调算子且T-10≠φ.本文引入了一种新迭代格式,利用Lyapunov泛函和广义投影算子等技巧,在Banach空间中证明了迭代序列弱收敛于极大单调算子T的零点的结论.  相似文献   

10.
苏维钢  钟怀杰 《东北数学》2005,21(4):439-446
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   

11.
We prove that the K-groups of the Banach algebra of bounded, linear operators on the pth James space , where 1 < p < , are given by and . Moreover, for each Banach space and each non-zero, closed ideal contained in the ideal of inessential operators, we show that and . This enables us to calculate the K-groups of for each Banach space which is a direct sum of finitely many James spaces and -spaces.  相似文献   

12.
In this paper, we investigate the strong convergence of an inexact proximal-point algorithm. It is known that the proximal-point algorithm converges weakly to a solution of a maximal monotone operator, but fails to converge strongly. Solodov and Svaiter (Math. Program. 87:189–202, 2000) introduced a new proximal-type algorithm to generate a strongly convergent sequence and established a convergence result in Hilbert space. Subsequently, Kamimura and Takahashi (SIAM J. Optim. 13:938–945, 2003) extended the Solodov and Svaiter result to the setting of uniformly convex and uniformly smooth Banach space. On the other hand, Rockafellar (SIAM J. Control Optim. 14:877–898, 1976) gave an inexact proximal-point algorithm which is more practical than the exact one. Our purpose is to extend the Kamimura and Takahashi result to a new inexact proximal-type algorithm. Moreover, this result is applied to the problem of finding the minimizer of a convex function on a uniformly convex and uniformly smooth Banach space. L.C. Zeng’s research was partially supported by the Teaching and Research Award Fund for Outstanding Young Teachers in Higher Education Institutions of MOE, China and by the Dawn Program Foundation in Shanghai. J.C. Yao’s research was partially supported by the National Science Council of the Republic of China.  相似文献   

13.
On Hereditarily Indecomposable Banach Spaces   总被引:1,自引:0,他引:1  
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   

14.
We continue the study of Uniformly Finitely Extensible Banach spaces (in short, UFO) initiated in Moreno and Plichko (2009) [39] and Castillo and Plichko (2010) [18]. We show that they have the Uniform Approximation Property of Pe?czyński and Rosenthal and are compactly extensible. We will also consider their connection with the automorphic space problem of Lindenstrauss and Rosenthal – do there exist automorphic spaces other than c0(I)c0(I) and ?2(I)?2(I)? – showing that a space all whose subspaces are UFO must be automorphic when it is Hereditarily Indecomposable (HI), and a Hilbert space when it is either locally minimal or isomorphic to its square. We will finally show that most HI – among them, the super-reflexive HI space constructed by Ferenczi – and asymptotically ?2?2 spaces in the literature cannot be automorphic.  相似文献   

15.
Let X be an infinite-dimensional complex Banach space and denote by B(X) the algebra of all bounded linear operators acting on X. It is shown that a surjective additive map Φ from B(X) onto itself preserves similarity in both directions if and only if there exist a scalar c, a bounded invertible linear or conjugate linear operator A and a similarity invariant additive functional ψ on B(X) such that either Φ(T) = cATA^-1 + ψ(T)I for all T, or Φ(T) = cAT*A^-1 + ψ(T)I for all T. In the case where X has infinite multiplicity, in particular, when X is an infinite-dimensional Hilbert space, the above similarity invariant additive functional ψ is always zero.  相似文献   

16.
Let φ: 𝔻 → 𝔻 and ψ: 𝔻 → ? be analytic maps. They induce a weighted composition operator ψ C φ acting between weighted Bloch type spaces and weighted Banach spaces of holomorphic functions. Under some assumptions on the weights, we give a necessary as well as a sufficient condition when such an operator is bounded resp. compact.  相似文献   

17.
18.
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  
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   

19.
In this paper, by employing the notion of generalized projection operators and the well-known Fan’s lemma, we establish some existence results for the variational inequality problem and the quasivariational inequality problem in reflexive, strictly convex, and smooth Banach spaces. We propose also an iterative method for approximate solutions of the variational inequality problem and we establish some convergence results for this iterative method. L. C. Zeng, His research was partially supported by the Teaching and Research Award Fund for Outstanding Young Teachers in Higher Education Institutions of MOE, China and by the Dawn Program Foundation, Shanghai, China. J. C. Yao, His research was partially supported by the National Science Council of the Republic of China  相似文献   

20.
Let X be a partially ordered real Banach space, let a,bX with ab. Let φ be a bounded linear functional on X. We say that X satisfies the box-optimization property (or X is a BOP space) if the box-constrained linear program: max 〈φ,x〉, s.t. axb, has an optimal solution for any φ,a and b. Such problems arise naturally in solving a class of problems known as interval linear programs. BOP spaces were introduced (in a different language) and systematically studied in the first author’s doctoral thesis. In this paper, we identify new classes of Banach spaces that are BOP spaces. We present also sufficient conditions under which answers are in the affirmative for the following questions:
  1. (i)
    When is a closed subspace of a BOP space a BOP space?
     
  2. (ii)
    When is the range of a bounded linear map a BOP space?
     
  3. (iii)
    Is the quotient space of a BOP space a BOP space?
     
  相似文献   

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