b-距离空间中α-(φ,ψ)压缩重合点定理

在b-距离空间中,建立了一类α-(φ,ψ)压缩重合点定理.这一结果将Yamaod等人的结果中的压缩系数s3放宽为sε,其中ε1.作为应用,给出了带有偏序关系的b-距离空间中的(φ,ψ)压缩重合点定理.这一结果可以推出Huang等人的一个主要结果.     

模糊距离空间中的循环φ-压缩映射的不动点定理

在模糊距离空间中建立了两类Boyd-Wong型非线性循环φ-压缩映射的不动点定理,这些结果是前人结果的改进和补充,此外,还得到了Alber-Guerre Delabriere型和Geraghty型的非线性循环φ-压缩映射的不动点定理.最后给出两个例子支持我们的结果.     

p-距离空间中的一类压缩映象的不动点定理

仿照距离空间,2-距离空间中的一些概念,引入了p-距离空间及p-距离空间中的一些基本概念.根据研究2-距离空间中不动点理论的思想和方法,利用泛函分析的理论,对p-距离空间中的不动点问题进行了研究.把2.距离空间中压缩型映像的不动点理论移植到了p-距离空间中,形成了p-距离空间中压缩型映像的一些基本不动点理论.其距.离空...     

偏序2-距离空间中压缩型映象的公共耦合不动点定理

在偏序2-距离空间中,研究了一类压缩型映象不动点的存在性和唯一性问题.利用映象对的ω-相容性条件,获得了此类映象的一个新的耦合重合点和耦合公共不动点定理.所得结果是度量空间中某些经典结果在偏序2-距离空间的进一步推广和发展.     

2-距离空间中平方型压缩映象的一个新的耦合公共不动点定理

在2-距离空间的框架下, 利用映象对的ω-相容性条件, 建立了一类新的平方型压缩条件, 讨论了此类映象耦合公共不动点的存在性和唯一性.证明了一个新的耦合公共不动点定理, 也提供了一个有效的例子来支持该文的新结果.该文的结果改善了之前文献中的相关结果.     

一致空间中带推广q-距离的(φ,Ψ,p)-弱压缩映射的不动点定理

在一致空间引入了推广的q-距离(特殊地,推广的P-距离)和关于推广q-距离序列完备的概念.通过运用推广的q-距离和新的完备性,在一致空间中建立了满足(φ,ψ,p)-弱压缩映射的不动点定理.     

模糊距离空间中几类非线性压缩不动点定理

在 Kaleva-Seikkala 型模糊距离空间中建立了 Boyd-Wong 型和 Alber-Guerre Delabriere型非线性压缩不动点定理.这些结果补充了 Xiao等人的几个结果.作为应用,获得了通常距离空间和Menger概率距离空间中的几个非线性不动点定理.     

一类不动点定理及其在微分方程中的应用

在完备的距离空间中,建立了一类含有广义变距离函数的压缩映射不动点定理.将这一结果应用于一阶常微分方程周期边值问题中,得到了方程存在唯一解的充分条件.我们的结果比已有结果的条件更弱且完全去掉了下解存在的条件.     

Banach空间中非线性Φ-伪压缩映象不动点的迭代逼近

本文研究了非线性拟西Φ-伪压缩映象与Φ-伪压缩映象的不动点的迭代逼近问题.研究结果表明:在任意实的Banac h空间E中,拟Φ-伪压缩映象与Φ-伪压缩映象T(T不必连续)的具误差的Ishikawa与Mann迭代序列强收敛于T的唯一不动点.所得结果不但改进和推广了最近一些文献的相关结果,而且也改进了定理的证明方法.     

偏距离空间上四个映射的公共不动点的存在性与唯一性

该文证明了偏距离空间上满足广义非线性压缩型的四个映射的公共不动点定理.最后,举例说明了该文压缩条件确实改进了目前一些文献中压缩条件.     

Fixed point theorems in metric spaces

In this paper, we establish two general theorems for equivalence between the Meir–Keeler type contractive conditions and the contractive definitions involving gauge functions. One of these theorems is an extension of a recent result of Lim (On characterization of Meir–Keeler contractive maps, Nonlinear Anal. 46 (2001) 113–120).     

A common fixed point theorem for compatible quasi contractive self mappings in metric spaces

A common fixed point theorem for weakly commuting quasi contractive self mappings with contracting orbital diameters in metric spaces [V. Berinde, A common fixed point theorem for quasi contractive type mappings, Ann. Univ. Sci. Budapest. 46 (2003) 81-90] is extended to the more general class of compatible quasi contractive self mappings. Our result does extend and generalize numerous related results in literature.     

On Branciari’s theorem for weakly compatible mappings

In a recent paper B. Samet and H. Yazidi [B. Samet, H. Yazidi, An extension of Banach fixed point theorem for mappings satisfying a contractive condition of integral type, Ital. J. Pure Appl. Math. (in press)] have obtained an interesting theorem for mappings satisfying a contractive condition of integral type. The aim of this note is to present a generalization of their main result.     

Generalized contractions on partial metric spaces

In the present paper, we give some fixed point theorems for generalized contractive type mappings on partial metric space. Also, a homotopy result is given.     

Minimal isometric dilations of operator cocycles

We obtain existence, uniqueness results for minimal isometric dilations of contractive cocycles of semigroups of unital *-endomorphisms ofB(H. This generalizes the result of Sz. Nagy on minimal isometric dilations of semigroups of contractive operators on a Hilbert space. In a similar fashion we explore results analogus to Sarason's characterization that subspaces to which compressions of semigroups are again semigroups are semi-invariant subspaces, in the context of cocycles and quantum dynamical semigroups.This research is supported by the Indian National Science Academy under Young Scientist Project.     

Berinde mappings in orbitally complete metric spaces

We give a fixed point theorem for a self-mapping satisfying a general contractive condition of integral type in orbitally complete metric spaces. Some examples are given to illustrate our obtained result.     

Generalized Coupled Fixed Point Results on Complex Partial Metric Space Using Contractive Condition

In this paper, we obtain coupled fixed point results on complex partial metric space under contractive condition. An example to support our result is presented.     

Contractive multifunctions, fixed point inclusions and iterated multifunction systems

We study the properties of multifunction operators that are contractive in the Covitz-Nadler sense. In this situation, such operators T possess fixed points satisfying the relation x∈Tx. We introduce an iterative method involving projections that guarantees convergence from any starting point x₀∈X to a point x∈XT, the set of all fixed points of a multifunction operator T. We also prove a continuity result for fixed point sets XT as well as a “generalized collage theorem” for contractive multifunctions. These results can then be used to solve inverse problems involving contractive multifunctions. Two applications of contractive multifunctions are introduced: (i) integral inclusions and (ii) iterated multifunction systems.     

Best proximity point theorems for contractive mappings

This article is concerned with some new best proximity point theorems for principal cyclic contractive mappings, proximal cyclic contractive mappings, and proximal contractive mappings. As a consequence, an interesting fixed point theorem, due to Edelstein, for a contractive mapping is obtained from all those best proximity point theorems.