Fixed point theorems for the sum of two weakly sequentially continuous mappings

In the present paper, we prove some Krasnosel’skii-Leray-Schauder type fixed point theorems for weak topology. Some fixed point theorems for the sum of two weakly sequentially continuous mappings are also presented. Our results extend and improve on ones from several earlier works.     

Fixed Point Theorems and a New System of Multivalued Generalized Order Complementarity Problems*

Some new fixed point and coupled fixed point theorems for multivalued increasing type mappings are obtained and a new system of multivalued generalized order complementarity problems is introduced in this paper. In terms of new fixed point and coupled fixed point theorems, we give some existance results of solutions for this new system of multivalued generalized order complementarity problems. The results presented in this paper extend and improve the corresponding results announced by Isac and Kostreva.     

Coincidence and fixed point theorems for nonlinear hybrid generalized contractions

In this paper we first prove some coincidence and fixed point theorems for nonlinear hybrid generalized contractions on metric spaces. Secondly, using the concept of an asymptotically regular sequence, we give some fixed point theorems for Kannan type multi-valued mappings on metric spaces. Our main results improve and extend several known results proved by other authors.     

On Fixed Point and Almost Fixed Point Problems of Lower Semicontinuous Type Multivalued Mappings

In the present paper, some new almost fixed point theorems and fixed point theorems for lower semicontinuous type multivalued mappings are obtained in metrizable H-spaces.     

Fixed points for cyclic orbital generalized contractions on complete metric spaces

We prove a fixed point theorem for cyclic orbital generalized contractions on complete metric spaces from which we deduce, among other results, generalized cyclic versions of the celebrated Boyd and Wong fixed point theorem, and Matkowski fixed point theorem. This is done by adapting to the cyclic framework a condition of Meir-Keeler type discussed in [Jachymski J., Equivalent conditions and the Meir-Keeler type theorems, J. Math. Anal. Appl., 1995, 194(1), 293–303]. Our results generalize some theorems of Kirk, Srinavasan and Veeramani, and of Karpagam and Agrawal.     

度量凸空间上拟收缩型映射族的唯一公共不动点

给出了完备度量凸度量空间上具有拟收缩条件的非自映射族的公共不动点的存在和唯一性定理,并根据该结果得到更一般形式的唯一公共不动点定理.该文的主要结果对文献中的许多同类型的不动点定理进行了改进和一般化.     

Fixed Point Theorems in Partially Ordered Metric Spaces and Existence Results for Integral Equations

We derive some new coincidence and common fixed point theorems for self-mappings satisfying a generalized contractive condition in partially ordered metric spaces. As applications of the presented theorems, we obtain fixed point results for generalized contraction of integral type and we prove an existence theorem for solutions of a system of integral equations.     

广义凸空间上重合点定理和极大极小不等式

利用已知的KKM型定理,在广义空间上得到若干个新的重合点定理和推广的Fan-Browder型不动点定理,并且讨论了Von Newmann-Sion型极大极小不等式.主要结果改进和推广了文献中的相应结论.     

On fixed point and almost fixed point problems of lower semicontinuous type multivalued mappings

In the present paper, some new almost fixed point theorems and fixed point theorems for lower semicontinuous type multivalued mappings are obtained in metrizable H-spaces.     

Fixed points and coincidences of mappings of partially ordered sets

Possibility of the reduction of a coincidence problem to a fixed point problem is investigated for one-valued and multivalued mappings of partially ordered sets. New fixed point theorems are proved. Connections of the obtained results with well-known fixed point theorems and some recent results on coincidences of two mappings are considered.     

局部凸空间中的不动点定理

证明了局部凸空间中非凸集上的上半连续凝集值映射的一个Ｌｅｒａｙ－Ｓｃｈａｕｄｅｒ型不动点定理,并推广了一些已知的不动点定理。     

Applications of Michael's selection theorems to fixed point theory

Applying some of Ernest Michael's selection theorems, from recent fixed point theorems on u.s.c. multimaps, we deduce generalizations of the classical Bolzano theorem, several fixed point theorems on multimaps defined on almost convex sets, almost fixed point theorems, coincidence theorems, and collectively fixed point theorems. These results are related mainly to Michael maps, that is, l.s.c. multimaps having nonempty closed convex values.     

Multivalued generalized nonlinear contractive maps and fixed points

We introduce some notions of generalized nonlinear contractive maps and prove some fixed point results for such maps. Consequently, several known fixed point results are either improved or generalized including the corresponding recent fixed point results of Ciric [L.B. Ciric, Multivalued nonlinear contraction mappings, Nonlinear Anal. 71 (2009) 2716-2723], Klim and Wardowski [D. Klim, D. Wardowski, Fixed point theorems for set-valued contractions in complete metric spaces, J. Math. Anal. Appl. 334 (2007) 132-139], Feng and Liu [Y. Feng, S. Liu, Fixed point theorems for multivalued contractive mappings and multivalued Caristi type mappings, J. Math. Anal. Appl. 317 (2006) 103-112] and Mizoguchi and Takahashi [N. Mizoguchi, W. Takahashi, Fixed point theorems for multivalued mappings on complete metric spaces, J. Math. Anal. Appl. 141 (1989) 177-188].     

An Accelerated Algorithm Involving Quasi-$\phi$-Nonexpansive Operators for Solving Split Problems

In this paper, an algorithm of inertial type for approximating solutions of split equality fixed point problems involving quasi-$\phi$-nonexpansive maps is proposed and studied in the setting of certain real Banach spaces. Weak and strong convergence theorems are proved under some conditions. Some applications of the theorems are presented. The results presented extend and improve some existing results. Finally, some numerical illustrations are presented to support our theorems and their applications.     

Equilibrium existence theorems in KKM spaces

An abstract convex space satisfying the KKM principle is called a KKM space. This class of spaces contains G$G$-convex spaces properly. In this work, we show that a large number of results in KKM theory on G$G$-convex spaces also hold on KKM spaces. Examples of such results are theorems of Sperner and Alexandroff–Pasynkoff, Fan–Browder type fixed point theorems, Horvath type fixed point theorems, Ky Fan type minimax inequalities, variational inequalities, von Neumann type minimax theorems, Nash type equilibrium theorems, and Himmelberg type fixed point theorems.     

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．     

Quasi-equilibrium problems with applications to infinite optimization and constrained games in general topological spaces

By applying a new Fan-Browder type fixed point point theorem due to author, an existence theorem of quasi-equilibrium problem is proved in general topological space. As applications, some existence theorems of solutions for noncompact infinite optimization problems and noncompact constrained game problems are obtained in general topological spaces. These theorems improve and generalize a number of important results in recent literature.     

局部FC-空间上的几乎不动点和不动点

利用古典的KKM原理的开[闭]形式得到FC-空间上的KKM型定理并给出局部FC-空间上的上[下]半连续映射的几乎不动点定理,最后给出在局部FC-空间上具有闭值且其值为FC-子空间的上半连续映射的不动点定理.     

Approximating the common fixed points of two sequences of uniformly quasi-Lipschitzian mappings in convex metric spaces

In this paper, a kind of Ishikawa type iterative scheme with errors for approximating a common fixed point of two sequences of uniformly quasi-Lipschitzian mappings is introduced and studied in convex metric spaces. Under some suitable conditions, the convergence theorems concerned with the Ishikawa type iterative scheme with errors to approximate a common fixed point of two sequences of uniformly quasi-Lipschitzian mappings were proved in convex metric spaces. The results presented in the paper generalize and improve some recent results of Wang and Liu (C. Wang, L.W. Liu, Convergence theorems for fixed points of uniformly quasi-Lipschitzian mappings in convex metric spaces, Nonlinear Anal., TMA 70 (2009), 2067-2071).     

H—度量空间中的广义KKM定理及其应用

定义了一个新的空间-H-度量空间并在H-度量空间中,得到了具有有限度量紧闭（开）值的广义H-KKM映像的广义H-KKM定理,这些定理推广了Khamsi和Yuan最近一系列结果。作为应用,还得到有限度量紧闭（开）覆盖的Ky Fan型匹配定理,不动点定理和极小极大不等式,这些结果统一和推广了近期的许多结果。