Banach空间中几乎渐近非扩张型映象的不动点的迭代逼近

在Banach空间中引入了一类新的几乎渐近非扩张型映象,概括了Banach空间中若干熟知的非线性的Lipschitz映象类与非Lipschitz映象类成特例;例如,熟知的非扩张映象类,渐近非扩张映象类与渐近非扩张型映象类.考虑了用于逼近几乎渐近非扩张型映象不动点的带误差的修改了的Ishikawa迭代序列的收敛性问题.关于Banach空间范数的S.S.Chang的不等式与H.K.Xu的不等式皆被用于做精确不动点与近似不动点间的误差估计.而且,张石生教授用于做带误差的修改了的Ishikawa迭代序列收敛性分析的方法(应用数学和力学,2001,22(1):23-31)被推广到几乎渐近非扩张型映象的情况.给出了用于求一致凸Banach空间中几乎渐近非扩张型映象不动点的带误差的修改了的Ishikawa迭代序列的新的收敛判据.并且,由该判据,立即得到了此类映象的带误差的修改了的Mann迭代序列的新的收敛判据.上述结果统一、改进与推广了张石生教授关于用带误差的修改了的Ishikawa与Mann迭代序列来逼近渐近非扩张型映象不动点方面的结果.     

一致等度连续的渐近拟伪压缩型映象的强收敛性

设E是实赋范线性空间.K是E中的非空凸子集.T1,T2是K上的自映象.当T1是一致等度连续的渐近拟伪压缩型映象,T2是广义一致Lipschitz映象时,研究了具误差的Isikawa型迭代序列强收敛于T1,T2公共不动点的充要条件.所得结果推广和改进了近期内的相应结果.     

关于伪单调平衡问题和不动点问题的粘滞-次梯度方法

本文介绍了一个新的逼近伪单调平衡问题的解和广义渐近λ-严格伪压缩映象不动点的粘滞-次梯度方法,在Hilbert空间中建立了关于伪单调平衡问题和一簇广义渐近λ-严格伪压缩映象公共不动点的强收敛定理,并在收敛性分析中去掉了映象的一致Lipschitz连续性条件.     

一般Banach空间中渐近非扩张型半群的不动点定理

该文首先在一般Banach空间中对渐近非扩张型半群证明了两个不动点存在定理,并由此给出了渐近非扩张型半群Mann型迭代序列的强收敛定理.该文的主要结果将Suzuki和Takahashi的相应结果推广到non-Lipschitzian半群情形.     

关于全连续映象的渐近不动点定理的推广

利用非线性全连续映象与线性全连续映象的关系讨论不动点的存在性往往是一种有效的方法。本文的目的在于利用 Ioffe 准扇代表单个线性全连续算子,考察某种“广义”渐近线性全连续映象的不动点的存在性。我们的工作推广了全连续映象的渐近不动点存在定理。     

一般Banach空间中非Lipschitzian可逆半群的不动点定理

首先在一般Banach空间中对渐近非扩张型左可逆半群给出了两个不动点存在性定理.同时利用这些结果,得到了渐近非扩张型左可逆半群迭代序列的强收敛定理.主要结果将一些已知结果推广至非Lipschitzian左可逆半群的情形,而且即使在交换半群情形它们也是新的.     

“渐近非扩张映象不动点具误差的迭代逼近”的注记

本文在去掉条件"T在D上一致渐近正则"的情况下,在一致凸Banach空间中给出了几个渐近拟非扩张型映象和渐近非扩张型映象不动点的迭代逼近定理.这些定理推广和发展了最近一些文献的相关成果,并且改进了定理的证明方法.     

非稠定分数次微分方程在非局部条件下解的存在性(英文)

本文利用积分半群理论,Krasnoselskii不动点定理与压缩映象原理研究了非稠定分数次发展方程在非局部条件下积分解的存在性与唯一性.     

渐近伪压缩映象的Ishikawa迭代序列强收敛的充要条件

在一般的实Banach空间中,研究Lipschitz渐近伪压缩映象和渐近非扩张映象不动点的迭代逼近问题.给出Ishikawa迭代序列强收敛的充要条件,所得结果改进和推广了张石生,肖建中等人的主要结果,修正和推广了朱玲娣等人的相应结果.     

可逆的渐近非扩张型半群的遍历定理

本文在Ｈｉｌｂｅｒｔ空间中证明了右可逆的连续渐近非扩张型半群的遍历保核收缩存在定理，并讨论了可控的连续渐近非扩张型半群的遍历收敛定理     

Kœnigs-type linearization models and asymptotic behavior of one-parameter semigroups

In this paper, we study linear-fractional models for one-parameter semigroups of holomorphic mappings via Schröder’s and Abel’s functional equations. By using some limit schemes in the spirit of K?nigs to solve those equation, we obtain new results on the asymptotic behavior of one-parameter semigroups having a boundary Denjoy-Wolff fixed point. In addition, we establish infinitesimal versions of the Burns-Krantz rigidity theorem for semigroups and their generators.     

Coefficient bounds for biholomorphic mappings which have a parametric representation

The main purpose of this paper is to prove a collection of new fixed point theorems for so-called weakly F-contractive mappings. By analogy, we introduce also a class of strongly F-expansive mappings and we prove fixed point theorems for such mappings. We provide a few examples, which illustrate these results and, as an application, we prove an existence and uniqueness theorem for the generalized Fredholm integral equation of the second kind. Finally, in Appendix A, we apply the Mönch fixed point theorem to prove two results on the existence of approximate fixed points of some continuous mappings.     

Fixed-Point Theorems for Generalized Nonexpansive Mappings

Using the concept of asymptotic center we obtain the existence of fixed points having preassigned location for a wider class of asymptotic nonexpansive mappings in a uniformly convex Banach space. This generalization leads us to get a recent result of Alfuraidan and Khamsi for continuous monotone asymptotic nonexpansive mappings as well as the classical fixed-point result of Geobel and Kirk for asymptotic nonexpansive mappings in a uniformly convex Banach space. Also we prove a fixed-point theorem for order preserving continuous maps on a quasiordered closed convex subset of a uniformly convex Banach sapce having monotone norm.     

New fixed point theorems for <Emphasis Type="Italic">P</Emphasis><Subscript>1</Subscript>-compact mappings in Banach spaces

E E. Browder and W. V. Petryshyn defined the topological degree for A- proper mappings and then W. V. Petryshyn studied a class of A-proper mappings, namely, P1-compact mappings and obtained a number of important fixed point theorems by virtue of the topological degree theory. In this paper, following W. V. Petryshyn, we continue to study P1-compact mappings and investigate the boundary condition, under which many new fixed point theorems of P1-compact mappings are obtained. On the other hand, this class of A-proper mappings with the boundedness property includes completely continuous operators and so, certain interesting new fixed point theorems for completely continuous operators are obtained immediately. As a result of it, our results generalize several famous theorems such as Leray-Schauder＇s theorem, Rothe＇s theorem, Altman＇s theorem, Petryshyn＇s theorem, etc.     

Strong convergence of modified Ishikawa iteration for two asymptotically nonexpansive mappings and semigroups

In this paper, we established strong convergence theorems for a common fixed point of two asymptotically nonexpansive mappings and for a common fixed point of two asymptotically nonexpansive semigroups by using the hybrid method in a Hilbert space. Moreover, we also proved a strong convergence theorem for a common fixed point of two nonexpansive mappings. Our results extend and improve the recent ones announced by Kim and Xu [T.W. Kim, H.W. Xu, Strong convergence of modified Mann iteration for asymptotically nonexpansive mappings and semigroups, Nonlinear Anal. 64 (2006) 1140–1152], Nakajo and Takahashi [K. Nakajo, W. Takahashi, Strong convergence theorems for nonexpansive mappings and nonexpansive semigroups, J. Math. Anal. Appl. 279 (2003) 372–379], and many others.     

Around Browder’s fixed point theorem for contractions

We revisit a fixed point theorem for contractions established by Felix Browder in 1968. We show that many definitions of contractive mappings which appeared in the literature after 1968 turn out to be equivalent formulations or even particular cases of Browder’s definition. We also discuss the problem of the existence of approximate fixed points of continuous mappings; in particular, we settle it in the affirmative for Browder contractions. Finally, we recall three problems concerning Browder contractions which remain unsolved. With great respect for Professor Felix E. Browder     

Multivalued fixed point in Banach algebra using continuous selection and its application to differential inclusion

In this paper, we provide some fixed point results using continuous selection given by Poonguzali et al. [15]. Also, using the selection theorem we discusse the existence of fixed point for the product of two multivalued mappings, that is, of the form $Ax\cdot Bx.$ Using those fixed point results, we give the existence of solution for a newly developed differential inclusion.     

Fixed points for weakly inward mappings in Banach spaces

S. Hu and Y. Sun [S. Hu, Y. Sun, Fixed point index for weakly inward mappings, J. Math. Anal. Appl. 172 (1993) 266-273] defined the fixed point index for weakly inward mappings, investigated its properties and studied the fixed points for such mappings. In this paper, following S. Hu and Y. Sun, we continue to investigate boundary conditions, under which the fixed point index for the completely continuous and weakly inward mapping, denoted by i(A,Ω,P), is equal to 1 or 0. Correspondingly, we can obtain some new fixed point theorems of the completely continuous and weakly inward mappings and existence theorems of solutions for the equations Ax=μx, which extend many famous theorems such as Leray-Schauder's theorem, Rothe's two theorems, Krasnoselskii's theorem, Altman's theorem, Petryshyn's theorem, etc., to the case of weakly inward mappings. In addition, our conclusions and methods are different from the ones in many recent works.     

Edelstein's fixed point theorem in topological spaces

An extension to topological spaces of a wellknown fixed point theorem of M. Edelstein for contractive mappings on metric spaces is presented. Results based on the generalized Edelstein's theorem are also established concerning the existence of fixed points of continuous selfmaps on a topological space. As a special case a compact starshaped subset of a linear topological space is considered. The results extend the fixed point theoremsfor nonexpansive mappings on a compact metric space of L.F.Guseman, Jr. and B.C. Peters, Jr.     

Minimax Problems for Set-Valued Mappings

In this article, by virtue of the Fan-Browder fixed point theorem, we first obtain a minimax theorem and establish an equivalent relationship between the minimax theorem and a cone saddle point theorem for scalar set-valued mappings. Then, by using scalarization functions, we investigate an existence theorem of the cone saddle point for set-valued mappings. Simultaneously, we also establish a minimax theorem for set-valued mappings.