射影平面上不动元素的若干性质

射影平面上存在直射变换下的不动元素的充要条件是直射变换式特征方程的系数行列式值为零;平面上的直射变换至少有一不动点与一不动直线,而且不动点和不动直线的数目相同;直射变换的不共线的不变点至多有三个;过一不动点至少有一不动直线;两不动点的连线是不动直线;不动直线上的点不一定都是不动点。     

当A~m为压缩时求A不动点的迭代程序及误差估计

<正> 许多泛函分析教材中都证明了定理:若完备度量空间X 上的自映射A:X→X 并不是但映射A~m(m 为大于1的定整数)是压缩的,则A 在X 上有唯一不动点,分析其证明过程知:A 与A~m 的不动点圆;而A~m 不动点的存在唯一性,则由Banach 不动点定理保证,由后面的定理可知,A 的不动点(设为x~(?),Ax~(?)=x~(?))因是A~m的不动点,故是     

锥度量空间上混合型膨胀映射族的唯一公共不动点

引进了一类混合型膨胀映射族,并在锥度量空间上证明了此类映射族具有唯一公共不动点的定理,同时给出了相应的不动点定理,推广和改进了文献中关于第I膨胀映射的相应的公共不动点和不动点定理.     

聚焦高考题中的高等数学背景(二)

1.以不动点原理为背景不动点原理是高等数学上一个重要的原理,也叫压缩映像原理或Banach不动点定理,完整的表达:完备的距离空间上,到自身的一个压缩映射存在唯一的不动点.用初等数学可以这么理解:连续映射f的定义域包含值域,则存在一个x使得f(x)=x.     

混合单调算子的两点拉伸型不动点定理

本文首次提出了混合单调算子不动点的两点拉伸型条件.同时,利用锥映象的不动点指数理论建立了一类特殊的两点拉伸型混合单调算子的不动点存在性定理,并将所得结论应用于带有超线性项的积分方程与微分方程上,得到了新的结论.因而在本质上推进了混合单调算子不动点问题的研究.     

锥度量空间上满足新的Lipschitz条件的三个映射的公共不动点

在没有正规条件的锥度量空间框架下,证明了具有Lipschitz条件的三个映射的公共不动点定理.同时,在具有偏序关系的锥度量空间上讨论了公共不动点存在问题.所得结果推广和改进了许多收缩型不动点定理和公共不动点定理.     

局部H—凸空间及其不动点定理

本文引入局部Ｎ—凸空间的概念，并得出局部Ｈ—凸空间上映象的两个不动点定理。它们包含著名的Ｓｃｈａｕｄｅｒ不动点定理和Ｂｒｏｗｄｅｒ不动点定理为特例。     

Hadzic不动点定理的改进

本文给出Ｍｅｎｇｅｒ空间上多值压缩型映象的一个新的不动点定理，它是Ｈｅｄｚｉｃ不动点定理在某种意义下的改进。利用它，我们得到了度量空间上多值映象的一个不动点定理，统一并推广了文［６－１０］的某些重要结果。     

路径跟踪方法求解无界非凸区域上的不动点问题

给出了求解一类无界非凸区域上不动点问题的路径跟踪方法.在适当的条件下,给出了不动点存在性的构造性证明,从而得到了路径跟踪方法的全局收敛性结果.研究结果为计算无界非凸区域上不动点问题提供了一种全局收敛性方法.     

求“不动点”问题

近年来 ,数学高考试题十分重视不动点问题的考查 ,通常以不动点为载体 ,与函数、数列、不等式、解析几何的知识进行综合 ,结合数学思想、方法、与时代信息融合一体 ,考查学生的能力 .深化能力立意 ,突出考查能力和素质的导向 .本文试图探索不动点问题 ,寻找其解题途径、规律和策略 .1　不动点与逻辑思维的整合不动点与逻辑思维的整合 ,考查学生吸收信息和处理信息的能力 .例 1　下述命题 :“若定义在Ｒ上的奇函数ｆ(ｘ)图象上存在有限个不动点 ,则不动点有奇数个”是否正确 ,若正确 ,请给予证明 ,若不正确 ,请举一反例 .解　命题正确 .∵ ｆ…     

Preservation of Sahlqvist fixed point equations in completions of relativized fixed point Boolean algebras with operators

We define Sahlqvist fixed point equations and relativized fixed point Boolean algebras with operators (relativized fixed point BAOs). We show that every Sahlqvist fixed point equation is preserved under completions of conjugated relativized fixed point BAOs. This extends the result of Givant and Venema (1999) to the setting of relativized fixed point BAOs.     

Leray-Schauder不动点定理的一个新证明

给出Leray-Schauder不动点定理的一个新证明.我们首先给出集值映射的焊接引理,利用集值映射的焊接引理和Kakutani不动点定理证明Leray-Schauder不动点定理,并证明Leray-Schauder不动点定理与Brouwer不动点定理等价.     

概率度量空间中若干新的不动点定理*

本文提出了Z-M-PN空间的概念,在概率度量空间中我们得到了若干新的不动点定理。同时,一些着名的不动点定理在概率度量空间中得到了推广,诸如:Schauder不动点定理、郭大钧不动点定理和Petryshyn不动点定理被推广到M-PN空间;Altman不动点定理被推广到Z-M-PN空间。     

New cone fixed point theorems for nonlinear multivalued maps with their applications

In this paper, we first establish some new types of fixed point theorems for nonlinear multivalued maps in cone metric spaces. From those results, we obtain new fixed point theorems for nonlinear multivalued maps in metric spaces and the generalizations of Mizoguchi–Takahashi’s fixed point theorem and Berinde–Berinde’s fixed point theorem. Some applications to the study of metric fixed point theory are given.     

Menger概率度量空间中Caristi型混合不动点定理

本文在Menger概率度量空间中引进Caristi型混合不动点概念,得到两个混合不动点定理和两个集值映象序列的公共混合不动点定理,我们的定理改进和推广了Caristi不动点定理及相关的近期重要结果.     

Distortion and stability of the fixed point property for non-expansive mappings

Let X be a Banach space. We say that X satisfies the fixed point property (weak fixed point property) if every non-expansive mapping defined from a convex closed bounded (convex weakly compact) subset of X into itself has a fixed point. We say that X satisfies the stable fixed point property (stable weak fixed point property) if the same is true for every equivalent norm which is close enough to the original one. Denote by P(X) the set formed by all equivalent norms with the topology of the uniform convergence on the unit ball of X. We prove that the subset of P(X) formed by the norms failing the fixed point property is dense in P(X) when X is a non-distortable space which fails the fixed point property. In particular, no renorming of ?₁ can satisfy the stable fixed point property. Furthermore, we show some examples of distortable spaces failing the weak fixed point property, which can be renormed to satisfy the stable weak fixed point property. As a consequence we prove that every separable Banach space can be renormed to satisfy the stable weak fixed point property.     

Generalized KKM theorems and common fixed point theorems

In this paper, we first prove a generalized KKM theorem, and then use this generalized KKM theorem to establish the generalized equi-KKM theorem, common fixed point theorems for a family of multivalued maps, and the Kakutani-Fan-Glicksberg fixed point theorem. We also show that an existence theorem of the common fixed point theorem is equivalent to the Kakutani-Fan-Glicksberg fixed point theorem.     

Generalizations of fixed point theorems and computation

As a powerful mechanism, fixed point theorems have many applications in mathematical and economic analysis. In this paper, the well-known Brouwer fixed point theorem and Kakutani fixed point theorem are generalized to a class of nonconvex sets and a globally convergent homotopy method is developed for computing fixed points on this class of nonconvex sets.     

Forbidden retracts for finite ordered sets of width at most four

The relationship between the fixed point property and forbidden retracts associated with a forgetful functor is formulated. Finite ordered sets of width at most four with fixed point free automorphisms are described. Linear time algorithms for deciding whether a finite ordered set of width two has the fixed point property and whether a finite ordered set of width at most three has a fixed point free automorphism are presented.     

L-空间中的KKM映射及不动点定理

引入了L-空间和L-空间上的KKM类映射，建立了关于该类映射的一些不动点定理，其中包括Schauder型和Fan-Browder型不动点定理．得到了L-空间中的KyFan匹配定理和叠合点定理．