1. Nonconvex proximal normal structure in convex metric spaces
- Author
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Olivier Olela Otafudu, Moosa Gabeleh, 26998513 - Gabeleh, Moosa, and 24803812 - Olela Otafudu, Olivier
- Subjects
47H09 ,Algebra and Number Theory ,Injective metric space ,010102 general mathematics ,Mathematical analysis ,0211 other engineering and technologies ,Structure (category theory) ,021107 urban & regional planning ,02 engineering and technology ,01 natural sciences ,$T$-regular reflexive pair ,nonconvex proximal normal structure ,Convex metric space ,Combinatorics ,46B20 ,best proximity pair ,strictly convex metric space ,Proximal Gradient Methods ,Point (geometry) ,0101 mathematics ,Analysis ,Mathematics - Abstract
Given that $A$ and $B$ are two nonempty subsets of the convex metric space $(X,d,\mathcal{W})$ , a mapping $T:A\cup B\to A\cup B$ is noncyclic relatively nonexpansive, provided that $T(A)\subseteq A$ , $T(B)\subseteq B$ , and $d(Tx,Ty)\leq d(x,y)$ for all $(x,y)\in A\times B$ . A point $(p,q)\inA\times B$ is called a best proximity pair for the mapping $T$ if $p=Tp$ , $q=Tq$ , and $d(p,q)=\operatorname {dist}(A,B)$ . In this work, we study the existence of best proximity pairs for noncyclic relatively nonexpansive mappings by using the notion of nonconvex proximal normal structure. In this way, we generalize a main result of Eldred, Kirk, and Veeramani. We also establish a common best proximity pair theorem for a commuting family of noncyclic relatively nonexpansive mappings in the setting of convex metric spaces, and as an application we conclude a common fixed-point theorem.
- Published
- 2016