Banach空间的强凸性

在本文中,我们定义了 Banach 空间的强凸性,它是强光滑的共轭概念,即若 X~*是强光滑的,则 X 是强凸的;若 X~*是强凸的,则 X 是强光滑的。我们还证明了若 X 是强凸的,则 X 是中点局部一致凸的;和若 Banach 空间 X是自反的,则 X 是强凸的当且仅当 X 具有(G)性质。     

正规强可遮空间的逆极限性质

证明了如下结果:设X=lim/←{Xσ,πσρ,Λ),|A|=λ,并且每个投射πσ∶X→Xσ是开满的,(A)若X是λ-仿紧的并且每个Xσ是正规强可遮空间,则X是正规强可遮空间;(B)若X是遗传λ-仿紧的并且每个Xσ是遗传正规且遗传强可遮空间,则X是遗传正规强可遮空间.     

关于增生算子方程解的Ishikawa迭代逼近

设X是任意实Banach空间,T:X→X是Lipschitz连续的增生算子.本文证明了,带误差的Ishikawa迭代序列强收敛到方程x Tx=f的唯一解.而且,还给Ishikawa迭代序列提供了一般的收敛率估计.利用该结果,本文推得,若T:X→X是Lipschitz连续的强增生算子,则带误差的Ishikawa迭代序列强收敛到方程Tx=f的唯一解.     

强伪压缩算子带误差的Ishikawa迭代的强稳定性

设X是任意实Banach空间，T：X→X是一Lipschitz强伪压缩算子，本给出T带误差的Ishikawa迭代过程的强稳定性，并给出一个涉及Lipschitz强增生算子T的非线性方程Tx=f迭代解的强稳定性。     

Orlicz空间的强端点

强端点与端点都是 Banach 空间几何学的基本概念,Banach 空间[X,‖·‖]的单位球面 S(X)上一点称为单位球 U(X)的端点,是指 U(X)中不含以 x_0为中点的正长度线段;x_0称为强端点,是指对任何ε>0,有δ>0,(1 δ)U(X)中不含以 x_0为中点长度为ε的线段。显然强端点必为端点。x_0是强端点的另一表述是,若 X 中元列{x_n}_1~∞,{y_n}_1~∞满足     

Banach空间中关于增生算子方程的迭代法的强收敛定理

设X是一实Banach空间,且T:X→X是Lipschitz连续的增生算子.在没有假设limn→∞αn=lim n→∞βn=0之下,本文证明了,Ishikawa迭代序列强收敛到方程x+Tx=f的唯一解,而且还对Ishikawa迭代序列提供了一般的收敛率估计.利用该结果,我们推得,当T:X→X是Lipschitz连续的强增生算子时, Ishikawa迭代序列强收敛到方程Tx=f的唯一解.     

关于增生算子方程的具误差的Ishikawa迭代序列的收敛率估计

设X是一实的Banach空间,TLX→X是—Lipschitz的增生算子;证明了具误差的Ishikawa迭代序列强收敛到x＋Tx=f的唯一解;得到一个一般的收敛率估计式．进一步得到：若了T：X→X是—Lipschitz的强增生算子,则具误差的Ishikawa迭代序列强收敛到Tx=f的唯一解．文中结果推广和发展了已有的相关结果．     

扰动m-增生算子方程的Ishikawa迭代程序

设X是光滑Banach空间,A:X→X是一致连续的m-增生算子,S:X→X是一致连续的φ--强增生算子,本文证明实光滑Banach空间上连续的m-增生算子是单值的且具误差的Ishikawa和Mann迭代序列强收敛到方程z=Sx+λAx的唯一解,其中z∈X,λ≥0.我们的结果改进和推广了近期文献中的相应结果.     

关于Banach空间中Lipschitz强伪压缩映象的带误差的Ishikawa型迭代序列

设X是任意实B&nach空间E的闭子空间,TX→X是Lipschitz强伪压缩映象,使得Tx*=x*,对某x*∈X…在没有条件limαn=nlimβn=0之下,本文证明了带误差的Ishikawa型迭代序列强收敛到x*.另外,相关结果又证明了,当TE→E是Lipschitz强增生算子时,带误差的Ishikawa型迭代序列强收敛到方程Tx=f的唯一解.     

B-Z-空间中的强凸性与k-强凸性

本文引入了B-Z-空间中强凸性、强光滑性、k-强凸性及k-强光滑性的概念,讨论了在B-Z-空间中强凸性与强光滑性、k-强凸性与k-强光滑性之间的关系,并且利用单位圆的切片证明了当B-Z-空间X是kx强凸的,则X是自反的;同时提出了B-Z-空间的(S)性质;最后得出了B-Z-空间的k-强凸性的相关性质.     

集值度量广义逆的存在性

设X,Y为Banach空间,T∈L(X,Y)为从X到Y的线性算子,D(T),N(T),R(T)分别为T的定义域,核空间与值域,使用算子T的自身性质,给出T具有集值度量广义逆T和R(T)D(T)的充分必要条件.     

赋范空间中渐近伪压缩映象不动点的迭代逼近

设x是赋范线性空间，D是x的非空子集．设T：D→x是一个一致L—Lipschitz的渐近伪压缩映象，F(T)表T的不动点集且F(T)非空．在迭代参数(αn)和(βn)的适当假设下，证明了修改了的具有误差项的Ishikawa和Mann迭代过程强收敛于T的不动点q．几个相关结果处理赋范空间中渐近非扩张映象不动点的迭代逼近问题．所得结果改进和推广了Chang，Park和Cho，Geobel和Kirl，Liu以及Schu等人的相关结果．     

Banach空间中带扰动的m-增生算子的映射定理

利用范数假设条件给出了带扰动的ｍ一增生算子的一些映射定理．其结果是：Ｂ＋Ｄ　　Ｒ（Ｔ＋Ｃ）并且ｉｎｔ（Ｂ＋Ｄ）　Ｒ（Ｔ＋Ｃ）的类型．其中Ｂ、Ｄ是实Ｂａｎａｃｈ空间Ｘ的子集,算子Ｔ：Ｘ　Ｄ（Ｔ）→２~Ｘ至少是ｍ一增生的,扰动算子 Ｃ： Ｘ　Ｄ（Ｃ）→Ｘ至少是紧、ｄｅｍｉ一半连续或完全连续的．这些结果推广和改进了已有文献的有关结果．     

THE EXISTENCE OF RADIAL LIMITS OF ANALYTIC FUNCTIONS IN BANACH SPACES

Let X be a comPlex Banach space and let D be the open unit disc in the complex plane.We shall denote by H"(D, X) the Banach space consisting of all uniformly bounded X-vaued analytic functions defined on D equipped with the norm llflloo = suP lIf(z)Il. Az eDcomplex Banach space X is said to have the analytic Radon-NikOdym property if eachelemellt f E Hoo(D,X) has radial limits almost everywhere on the torus T = {e": 0 E[0, 2x]} (see [1]), this means that for almost all 0 C [0,27l, 9W…     

没有Lipschitz假设的ψ-半压缩映象的不动点与ψ-强拟增生算子方程解的逼近

设X为实一致光滑Banach空间,T:D(T)∈X→X为ψ-半压缩映象且在它的不动点q处是局部有界的.本文证明了Mann迭代与Ishikawa迭代过程强收敛于T的唯一不动点g.几个相关的结果处理ψ-强拟增生算子方程的解的迭代构造.本文所得到的结果扩展并推广了Xu和Roach,Zhou和Jia等人的相应结果.     

Banach 空间中极大单调算子扰动的值域

设X为实Banach空间, T:D(T)(?)X→2X*为极大单调算子, C: D(T)(?)X→X*为有界算子(未必连续),而C(T+J)-1为紧算子．本文在上述假设条件下,通过附加一定的边界条件应用Leray-Schauder度理论研究了下述包含关系:0∈(T+C)(D(T)∩ BQ(0)),0∈(T+C)(D(T)∩ BQ(0));以及S(?)R(T+C), intS(?)intR(T+C)(其中S(?) X*);B+D(?)R(T+C),int(B+D)(?)intR(T+C)(其中 B(?)X*,D(?)X*)的可解性,得出了一些新的结论．     

Zeros of accretive operators

In the investigation of accretive operators in Banach spaces X, the existence of zeros plays an important role, since it yields surjectivity results as well as fixed point theorems for operators S such that I-S is accretive. Let D?X and T: D→X an operator such that the initial value problems (1) u′(t)=-Tu(t), u(0)=x εD are solvable. Then T has a zero iff (1) has a constant solution for some xεD. Under certain assumptions on D and T it is possible to show that (1) has a unique solution u(t,x) on [0,∞), for every xεD. In this case, define U(t): D→D by U(t)x=u(t,x). If T is accretive it turns out that U(t) is nonexpansive for every t≥0. This fact constitutes the basis for several authors concerned with this subject. They proceed with assumptions on D and X ensuring either that the U(t) must have a common fixed point x_o or that U(_p) has a fixed point x_p for every p≥0. In the first case, U(t)x_o is a constant solution of (1), whence Tx_o=0. In the second case, U(t)x_p is a p-periodic solution of (1). Hence, one has to impose additional conditions on T which imply that a p-periodic solution must be constant, for some p>0. The main purpose of the present paper is to show that, in certain situations, either the operators U(t) are actually strict contractions or T may be approximated by operators T_n such that the corresponding U_n(t) are strict contractions. Thus, we obtain several results in general Banach spaces and a unification of some results in special spaces.     

不具有性质(wa)的拓扑空间

设（X，T）是拓扑空间，如果对于任意的开覆盖u和任意的稠密子集D存在X的离散子集F∪→D使得St(F,u)=∪{U∈u:U∩F≠φ}=X，则称（X，T）具有性质（wa)，每一正规空间都具有性质（wa)。M.V.Matveev举例说明了T1空间可以不具有性质(wa)，本文证明了存在很多Hausdorff空间不具有性质（wa)，且进一步举例说明了Tychonoff空间可以不具有性质（wa)，这些结果回答了Matveev的问题。     

关于B-凸空间及其上黎斯算子West分解

给出 Ｂａｎａｃｈ空间列｛Ｘｉ｝ｉ＝１∞的 ｌｐ乘积Ｂ－凸的特征刻划, 证明Ｂ－凸空间上的每个黎斯算子可Ｗｅｓｔ分解,即分解成一个紧算子和一个拟幂 零算子的和．     

Periodic Solutions of Third-order Differential Equations with Finite Delay in Vector-valued Functional Spaces

In this paper, we study the well-posedness of the third-order differential equation with finite delay(P_3): αu'"(t) + u"(t) = Au(t) + Bu'(t) + Fut +f(t)(t ∈ T := [0,2π]) with periodic boundary conditions u(0) = u(2π), u'(0) = u"(2π),u"(0)=u"(2π) in periodic Lebesgue-Bochner spaces Lp(T;X) and periodic Besov spaces B_(p,q)~s(T;X), where A and B are closed linear operators on a Banach space X satisfying D(A) ∩ D(B) ≠ {0}, α≠ 0 is a fixed constant and F is a bounded linear operator from Lp([-2π, 0]; X)(resp. Bp,qs([-2π, 0]; X)) into X, ut is given by ut(s) = u(t + s) when s ∈ [-2π,0]. Necessary and sufficient conditions for the Lp-well-posedness(resp. B_(p,q)~s-well-posedness)of(P_3) are given in the above two function spaces. We also give concrete examples that our abstract results may be applied.