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Related papers: Generic nonexpansive Hilbert space mappings

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We prove that a closed convex subset $C$ of a real Hilbert space $X$ has the fixed point property for $(c)$-mappings if and only if $C$ is bounded. Some convergence results about the iterations are obtained.

Functional Analysis · Mathematics 2025-11-04 Sami Atailia , Abdelkader Dehici , Najeh Redjel

A well-known result of W. Ray asserts that if $C$ is an unbounded convex subset of a Hilbert space, then there is a nonexpansive mapping $T$: $C\to C$ that has no fixed point. In this paper we establish some common fixed point properties…

Functional Analysis · Mathematics 2020-01-23 Anthony T. -M. Lau , Yong Zhang

This paper seeks to advance the theory of nonexpansive mappings by introducing and exploring a novel class of nonexpansive type mappings, which we aptly designate as perimetric nonexpansive mappings. We establish that the collection of…

Functional Analysis · Mathematics 2025-08-12 Anish Banerjee , Hiranmoy Garai , Pratikshan Mondal , Lakshmi Kanta Dey

Motivated by the well-known cases of the real Hilbert ball and complete R-trees, being both particular cases of CAT(-1) spaces, we give an affirmative answer to the question of whether the geodesically boundedness property is a necessary…

Metric Geometry · Mathematics 2014-08-01 Bozena Piatek

We show that the typical nonexpansive mapping on a small enough subset of a CAT($\kappa$)-space is a contraction in the sense of Rakotch. By typical we mean that the set of nonexpansive mapppings without this property is a $\sigma$-porous…

Functional Analysis · Mathematics 2021-08-06 Christian Bargetz , Michael Dymond , Emir Medjic , Simeon Reich

Let $C$ be a convex subset of a locally convex space. We provide optimal approximate fixed point results for sequentially continuous maps $f\colon C\to\bar{C}$. First we prove that if $f(C)$ is totally bounded, then it has an approximate…

Functional Analysis · Mathematics 2013-02-27 Cleon S. Barroso , Ondřej F. K. Kalenda , Michel P. Rebouças

In this paper we generalize to unbounded convex subsets C of hyperbolic spaces results obtained by W.A. Kirk and R. Espinola on approximate fixed points of nonexpansive mappings in product spaces $(C\times M)_\infty$, where M is a metric…

Functional Analysis · Mathematics 2007-05-23 Ulrich Kohlenbach , Laurentiu Leustean

Suppose that E is a Banach space, {\tau} a topology under which the norm of E becomes {\tau}-lower semicontinuous and S a commuting family of {\tau}-continuous nonexpansive mappings defined on a {\tau}-compact convex subset C of E: It is…

Functional Analysis · Mathematics 2018-11-05 Sławomir Borzdyński

In this paper, we consider the CQ projection method and the shrinking projection method given by a finite family of nonexpansive mappings of the unit sphere of a real Hilbert space, and prove strong convergence theorems to common fixed…

Functional Analysis · Mathematics 2020-02-18 Tatsuki Ezawa

We use $KKM$ theorem to prove the existence of a new fixed point theorem for non-expansive mapping:Let M be a bounded closed convex subset of Hilbert space H, and $A:M\rightarrow M$ be a non-expansive mapping, then exists a fixed point of A…

Functional Analysis · Mathematics 2012-08-07 Chunyan Yang

In this paper, we discuss characterizations of common fixed points of commutative semigroups of nonexpansive mappings. We next prove convergence theorems to a common fixed point. We finally discuss nonexpansive retractions onto the set of…

Functional Analysis · Mathematics 2007-05-23 T. Suzuki

In this paper, we first introduce and study the notion of random Chebyshev centers. Further, based on the recently developed theory of stable sets, we introduce the notion of random complete normal structure so that we can prove the two…

Functional Analysis · Mathematics 2024-08-22 Xiaohuan Mu , Qiang Tu , Tiexin Guo , Hong-Kun Xu

Let $D$ be a bounded domain in a complex Banach space. According to the Earle-Hamilton fixed point theorem, if a holomorphic mapping $F : D \mapsto D$ maps $D$ strictly into itself, then it has a unique fixed point and its iterates converge…

Complex Variables · Mathematics 2011-05-17 David Shoikhet

We consider semidifferentiable (possibly nonsmooth) maps, acting on a subset of a Banach space, that are nonexpansive either in the norm of the space or in the Hilbert's or Thompson's metric inherited from a convex cone. We show that the…

Functional Analysis · Mathematics 2014-03-12 Marianne Akian , Stephane Gaubert , Roger Nussbaum

We study the computational difficulty of the problem of finding fixed points of nonexpansive mappings in uniformly convex Banach spaces. We show that the fixed point sets of computable nonexpansive self-maps of a nonempty, computably weakly…

Logic · Mathematics 2017-01-11 Eike Neumann

We investigate typical properties of nonexpansive mappings on unbounded complete hyperbolic metric spaces. For two families of metrics of uniform convergence on bounded sets, we show that the typical nonexpansive mapping is a Rakotch…

Functional Analysis · Mathematics 2023-03-21 Christian Bargetz , Simeon Reich , Daylen Thimm

This paper presents new approaches to the fixed point property for nonexpansive mappings in L^1 spaces. While it is well-known that L^1 fails the fixed point property in general, we provide a complete and self-contained proof that…

Functional Analysis · Mathematics 2025-09-15 Faruk Alpay , Hamdi Alakkad

We extend to $p$-uniformly convex spaces tools from the analysis of fixed point iterations in linear spaces. This study is restricted to an appropriate generalization of single-valued, pointwise $\alpha$-averaged mappings. Our main…

Functional Analysis · Mathematics 2021-04-26 Arian Bërdëllima , Florian Lauster , D. Russell Luke

In this paper, using Kronecker's theorem, we discuss the set of common fixed points of an n-parameter continuous semigroup of mappings. We also discuss convergence theorems to a common fixed point of an n-parameter nonexpansive semigroup.

Functional Analysis · Mathematics 2007-05-23 Tomonari Suzuki

In this paper, first we introduce a new mapping for finding a common fixed point of an infinite family of nonexpansive mappings then we consider iterative method for finding a common element of the set of fixed points of an infinite family…

Functional Analysis · Mathematics 2015-02-18 Vahid Darvish , S. M. Vaezpour
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