Fixed points of nonexpansive mappings on star-shaped subsets of a convex metric space

In this paper, we give some characteristic properties of star-shaped sets which include a subset of a convex metric space. Using the characteristic properties, we discuss the existence problems of fixed points of nonexpansive type mappings on star-shaped subsets of convex metric spaces, which generalize the recent results obtained by Ding Xie-ping, Beg and Azam. Finally, we give an example which shows that our generalizations are essential.     

Common fixed point theorems for (sub) compatible and set-valued generalized nonexpansive mappings in complete convex metric spaces

In this paper,using some conditions of(sub)compatibility between a set-valuedmapping and a single-valued mapping,we establish a necessary and sufficientcondition and a sufficient condition for set-valued generalized nonexpansive mappingsto have a unique common fixed point in complete convex metric spaces.The resultsimprove,extend and develop the main results in[2-7].     

Quasi-Equilibrium Problems and Constrained Multiobjective Games in Generalized Convex Space

ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔＸａｎｄＹｂｅｎｏｎｅｍｐｔｙｓｅｔｓａｎｄ2 ＸｂｅｔｈｅｆａｍｉｌｙｏｆａｌｌｓｕｂｓｅｔｓｏｆＸ .ＬｅｔＴ :Ｘ→Ｙｂｅａｓｉｎｇｌｅ＿ｖａｌｕｅｄｍａｐｐｉｎｇ ,Ａ :Ｘ→ 2 Ｘｂｅａｓｅｔ＿ｖａｌｕｅｄｍａｐｐｉｎｇ ,ψ :Ｘ×Ｙ×Ｘ→Ｒ∪ ±∞ ａｎｄｆ:Ｘ×Ｙ→Ｒ∪ ±∞ ｂｅｔｗｏｆｕｎｃｔｉｏｎｓ.Ｔｈｅｇｅｎｅｒａｌｑｕａｓｉ＿ｅｑｕｉｌｉｂｒｉｕｍｐｒｏｂｌｅｍＧＱＥＰ (Ｔ ,Ａ ,ψ)ｉｓｔｏｆｉｎｄ ^ｘ∈Ｘｓｕｃｈｔｈａｔ^ｘ∈Ａ( ^ｘ) ,ψ( ^ｘ ,Ｔ^ｘ ,ｙ)≤ 0…     

MAXIMAL ELEMENTS FOR G_B-MAJORIZED MAPPINGS IN PRODUCT G-CONVEX SPACES AND APPLICATIONS (Ⅰ)

IntroductionItiswell_knownthattheexistenceofmaximalelementsforset_valuedmappingsintopological(vector)spacesanditsimportantapplicationstomathematicaleconomieshavebeenstudiedextensivelybymanyauthorsinbothmathematicsandeconomics.Forexistenceresultsofmaximalelementsofvariousclassesofset_valuedmappingsandtheirapplicationstomathematicaleconomiesandotherbranchesofmathematics,thereadermayconsultRefs.[1～ 2 7]andthereferencestherein .LetXbeatopologicalspaceandY =∏i∈IYibeaproductofnonemptyconvexsetY…     

Lie symmetries of geodesic equations and projective collineations

We prove a theorem which relates the Lie symmetries of the geodesic equations in a Riemannian space with the collineations of the metric. We apply the results to Einstein spaces and spaces of constant curvature. Finally with examples we show the use of the results.     

EKELAND’S VARIATIONAL PRINCIPLE AND CARISTI’S COINCIDENCE THEOREM FOR SET-VALUED MAPPINGS IN PROBABILISTIC METRIC SPACES

By using the partial ordering method,a more general type,of Ekeland’s ariational principle and a set-valued Caristi’s coincidence theorem in probabilistic metric spaces are obtained.In addition,a direct simple proof of the equivalence between these two theorems in probabilistic metric spaces is given.     

NEW VERSION OF KKMTHEOREM IN PROBABILISTIC METRIC SPACES WITH APPLICATIONS

ＮＥＷＶＥＲＳＩＯＮＯＦＫＫＭＴＨＥＯＲＥＭＩＮＰＲＯＢＡＢＩＬＩＳＴＩＣＭＥＴＲＩＣＳＰＡＣＥＳＷＩＴＨＡＰＰＬＩＣＡＴＩＯＮＳＺｈａｎｇＳｈｉｓｈｅｎｇ（张石生）ＹｅｏｌＪｅＣｈｏ（赵烈济）ＷｕＸｉａｎｇ（吴鲜）（ＲｅｃｅｉｖｅｄＭａｙ７，１９９...     

BASIC THEORY AND APPLICATIONS OF PROBABILISTIC METRIC SPACES (Ⅰ)

This paper is devoted to the study of the basic theory and applications of probabilistic metric spaces (PM-space). In this paper the topological structure and properties for PM-space are considered. The conditions of metrization and the form of metric functions for PM-spaces. Menger PM-spaces and probabilistic normed linear spaces (PN-space) are given and the characterizations of various probabilistically bounded sets are presented. As applications we utilize these results obtained in this paper to study the linear operator theory and fixed point theory on PM-spaces. Projects supported by the Science Fund of the Chinese Academy of Sciences.     

Fixed Points on Two Complete and Compact Metric Spaces

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｆｏｌｌｏｗｉｎｇｒｅｌａｔｅｄｆｉｘｅｄｐｏｉｎｔｔｈｅｏｒｅｍｗａｓｐｒｏｖｅｄｉｎ [1 ] .Ｔｈｅｏｒｅｍ 1　Ｌｅｔ(Ｘ ,ｄ)ａｎｄ (Ｙ ,ρ)ｂｅｃｏｍｐｌｅｔｅｍｅｔｒｉｃｓｐａｃｅｓ,ｌｅｔＴｂｅａｍａｐｐｉｎｇｏｆＸｉｎｔｏＹａｎｄｌｅｔＳｂｅａｍａｐｐｉｎｇｏｆＹｉｎｔｏＸｓａｔｉｓｆｙｉｎｇｔｈｅｉｎｅｑｕａｌｉｔｉｅｓρ(Ｔｘ,ＴＳｙ) ≤ｃｍａｘ ｄ(ｘ ,Ｓｙ) ,ρ(ｙ,Ｔｘ) ,ρ(ｙ,ＴＳｙ) ,ｄ(Ｓｙ ,ＳＴｘ) ≤ｃｍａｘ ρ(ｙ ,Ｔｘ) ,ｄ(ｘ,Ｓｙ) ,ｄ(ｘ ,ＳＴｘ)…     

Morse Decomposition of Semiflows on Topological Spaces

This paper studies Morse decompositions of discrete and continuous-time semiflows on compact Hausdorff topological spaces. We extend two classical results which are well-known facts for flows on compact metric spaces: the characterization of the Morse decompositions through increasing sequences of attractors and the existence of Lyapunov functions.     

CONTINUOUS SELECTION THEOREMS FOR FAN-BROWDER MAPPINGS IN TOPOLOGICAL SPACES AND THEIR APPLICATIONS

The concept of Fan-Browder mappings was first introduced in topological spaces without any convex structure. Then a new continuous selection theorem was obtained for the Fan-Browder mapping with range in a topological space without any convex structure and noncompact domain. As applications, some fixed point theorems, coincidence theorems and a nonempty intersection theorem were given. Both the new concepts and results unify and extend many known results in recent literature.     

Ergodic theorem for infinite iterated function systems

1IntroductionandProblem IteratedFunctionSystems(IFS)theorycanbesaidtobethecontinuationanddevelopment ofdynamicalsystemtheory.DynamicalsystemstheorydealswithiterationofonemapbutIFS theorydealswithiterationofmanymaps. IFStheory’srootwasveryearlybutthebeginningofactivedevelopmentwasHutchinson’s paper(1981).Heresearchedselfsimilarityoffractalsetsusingsystemoffinitenumberofsimilar contractionmapsofRn.Barnsleycalledafinitesetofcontractionmappsasaniteratedfunction systemsandsystemizedIFStheo…     

Some new fixed point theorems in probabilistic metric spaces

ＳＯＭＥＮＥＷＦＩＸＥＤＰＯＩＮＴＴＨＥＯＲＥＭＳＩＮＰＲＯＢＡＢＩＬＩＳＴＩＣＭＥＴＲＩＣＳＰＡＣＥＳｚｈｕＣｈｕａｎ－ｘｉ（朱传喜）（ＭａｔｈｅｍａｔｉｅｓＤｉｖｉｓｉｏｎ,Ｎａｎｃｈａｎｇ．Ｕｎｉｖｅｒｓｉｔｙ,Ｎａｎｃｈａｎｇ）（Ｒｅｃｅｉｖ...     

MAXIMAL ELEMENTS FOR GB-MAJORIZED MAPPINGS IN PRODUCT G-CONVEX SPACES AND APPLICATIONS (Ⅰ)

A new family of set-valued mappings from a topological space into generalized convex spaces was introduced and studied. By using the continuous partition of unity theorem and Brouwer fixed point theorem, several existence theorems of maximal elements for the family of set-valued mappings were proved under noncompact setting of product generalized convex spaces. These theorems improve, unify and generalize many important results in recent literature. Contributed by DING Xie-ping Foundation items: the National Natural Science Foundation of China (19871059); the Natural Science Foundation of Education Department of Sichuan Province of China ([2000]25) Biography: DING Xie-ping (1938∼)     

Maximal elements of condensing preference maps in locally convex Hausdorff spaces

Two existence theorems of maximal elements of condensing preference maps in locallyconvex Hausdorff spaces are proved which generalize the recent results of Mehta.One ofthem positively answers the Open problem mentioned by Mehta.     

Quasi-equilibrium problems in noncompact generalized convex spaces

ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔＸａｎｄＹｂｅｎｏｎｅｍｐｔｙｓｅｔｓａｎｄ2ＸｂｅｔｈｅｆａｍｉｌｙｏｆａｌｌｓｕｂｓｅｔｓｏｆＸ.ＬｅｔＴ:Ｘ→Ｙｂｅａｓｉｎｇｌｅ＿ｖａｌｕｅｄｍａｐｐｉｎｇ,Ａ:Ｘ→2Ｘｂｅａｓｅｔ＿ｖａｌｕｅｄｍａｐｐｉｎｇａｎｄｆ:Ｘ×Ｙ→Ｒ∪±∞ｂｅａｆｕｎｃｔｉｏｎ.Ｔｈｅｑｕａｓｉ＿ｅｑｕｉｌｉｂｒｉｕｍｐｒｏｂｌｅｍＱＥＰ(Ｔ,Ａ,ｆ)ｉｓｔｏｆｉｎｄ^ｘ∈Ｘｓｕｃｈｔｈａｔ^ｘ∈Ａ(^ｘ),ｆ(^ｘ,Ｔ^ｘ)≤ｆ(ｙ,Ｔ^ｘ),　　ｙ∈Ａ(^ｘ).(1)ＴｈｅＱＥＰ(Ｔ,Ａ,ｆ)ｗａｓｉｎｔｒｏｄ…     

Ricci Curvature of Finite Markov Chains via Convexity of the Entropy

We study a new notion of Ricci curvature that applies to Markov chains on discrete spaces. This notion relies on geodesic convexity of the entropy and is analogous to the one introduced by Lott, Sturm, and Villani for geodesic measure spaces. In order to apply to the discrete setting, the role of the Wasserstein metric is taken over by a different metric, having the property that continuous time Markov chains are gradient flows of the entropy. Using this notion of Ricci curvature we prove discrete analogues of fundamental results by Bakry–Émery and Otto–Villani. Further, we show that Ricci curvature bounds are preserved under tensorisation. As a special case we obtain the sharp Ricci curvature lower bound for the discrete hypercube.     

Interative approximation of fixed points for almost asymptotically nonexpansive type mappings in Banach spaces

IntroductionThroughoutthispaperweassumethatEisarealBanachspace ,E isthedualspaceofE ,DisanonemptysubsetofEandJ:E →2 E isthenormalizeddualitymappingdefinedbyJ(x) =f∈E :〈x ,f〉=‖x‖·‖f‖,‖f‖=‖x‖,　　 x∈E .　　Definition 1　LetT :D →Dbeamapping .1 )Tissaidtobeasymptoticallynonexpansive[1],ifthereexistsasequence kn [1 ,∞)withlimn→∞kn =1suchthat　　　　　‖Tnx-Tny‖≤kn‖x-y‖forall　　x ,y∈D ,n≥0 ;(1 )　　2 )Tissaidtobeofasymptoticallynonexpansivetype[2 ],if　　　　　lims…     

The theory and applications of generalized H-space

This paper brings forward the concept of generalized H-spaces which extends the concepts of H-spaces and almost probabilistic metric spaces.In this paper,the uniformity and properties far generalized H-space are considered.The conditions of metrization and the form of metric functions for generalized H-spaces,H-spaces and Menger PM-spaces are given and the characteristics of completeness and compactness for generalized H-spaces are presented.The results of this paper generalize and unify some recent results of[1-2,8,10].     

Noncompact infinite optimization and equilibria of constrained games in generalized convex spaces

ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔＩｂｅａｎｙ (ｆｉｎｉｔｅｏｒｉｎｆｉｎｉｔｅ)ｉｎｄｅｘｓｅｔａｎｄｆｏｒｅａｃｈｉ∈Ｉ,Ｘｉｂｅａｔｏｐｏｌｏｇｉｃａｌｓｐａｃｅ.ＷｅｕｓｅｔｈｅｎｏｔａｔｉｏｎＸ =∏ｉ∈ＩＸｉ　ａｎｄ　Ｘｉ=∏ｊ∈Ｉ,ｊ≠ｉＸｊ.Ｆｏｒｅａｃｈｘ∈Ｘ ,ｘｉｄｅｎｏｔｅｓｉｔｓｉｔｈｃｏｏｒｄｉｎａｔｅａｎｄｘｉｔｈｅｐｒｏｊｅｃｔｉｏｎｏｆｘｏｎＸｉ.Ｗｒｉｔｅｘ=(ｘｉ,ｘｉ) .Ｆｏｒｅａｃｈｉ∈Ｉ,ｌｅｔＦｉ:Ｘｉ → 2 Ｘｉｂｅａｓｅｔ＿ｖａｌｕｅｄｍａｐｐｉｎｇａｎｄｆｉ:Ｘ →Ｒ …