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Related papers: On a converse to Banach's Fixed Point Theorem

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Let B be any Lp space for p in (1,infty) or any Banach space isomorphic to a Hilbert space, and k be a nonnegative integer. We show that if n is at least 4, then the universal lattice Gamma =SL_n (Z[x1,...,xk]) has property (F_B) in the…

Functional Analysis · Mathematics 2011-06-08 Masato Mimura

In this article, we consider Kannan type contractive self-map $T$ on a metric space $(X,d)$ such that \[d(Tx,Ty)<\frac{1}{2}\{d(x,Tx)+d(y,Ty)\} \mbox{ for all } x \neq y \in X, \] and establish some new fixed point results without taking…

Functional Analysis · Mathematics 2017-07-21 Hiranmoy Garai , Tanusri Senapati , Lakshmi Kanta Dey

For every couple of Hausdorff functions $ \psi$ and $\varphi $ verifying some mild assumptions, there exists a compact subset $ K $ of the Baire space such that the $ \varphi$-Hausdorff measure and the $ \psi$-packing measure on $ K$ are…

Functional Analysis · Mathematics 2025-11-10 Mathieu Helfter

We investigate the connections between UC and UC* properties for ordered pairs of subsets (A,B) in metric spaces, which are involved in the study of existence and uniqueness of best proximity points. We show that the $UC^{*}$ property is…

Functional Analysis · Mathematics 2023-09-13 Vasil Zhelinski , Boyan Zlatanov

For a bounded closed convex set $K$, in this note, we study the FPP for $\alpha$-H\"older nonexpansive maps, i.e. mappings $T\colon K\to K$ for which $\|T x -Ty\| \leq\| x - y\|^\alpha$ for all $x, y\in K$, $\alpha\in (0,1)$. First, we note…

Functional Analysis · Mathematics 2022-12-20 Cleon S. Barroso

The aim of this paper is to establish some metrical coincidence and common fixed point theorems with an arbitrary relation under an implicit contractive condition which is general enough to cover a multitude of well known contraction…

General Mathematics · Mathematics 2017-01-13 Md Ahmadullah , Mohammad Imdad , Mohammad Arif

The purpose of this paper is devoted to studying representation of measures of non generalized compactness, in particular, measures of noncompactness, of non-weak compactness, and of non-super weak compactness, etc, defined on Banach spaces…

Functional Analysis · Mathematics 2021-03-15 Xiaoling Chen , Lixin Cheng

We make some remarks on the global shape of continuous convex functions defined on a Banach space $Z$. Among other results we prove that if $Z$ is separable then for every continuous convex function $f:Z\to\mathbb{R}$ there exist a unique…

Functional Analysis · Mathematics 2020-01-29 Daniel Azagra

We show that there are no nontrivial surjective uniformly asymptotically regular mappings acting on a metric space and derive some consequences of this fact. In particular, we prove that a jointly continuous left amenable or left reversible…

Functional Analysis · Mathematics 2016-12-20 Sławomir Borzdyński , Andrzej Wiśnicki

Motivated by the local theory of Banach spaces we introduce a notion of finite representability for metric spaces. This allows us to develop a new technique for comparing the generalized roundness of metric spaces. We illustrate this…

Functional Analysis · Mathematics 2016-08-15 Lukiel Levy-Moore , Margaret Nichols , Anthony Weston

We work in set-theory without choice ZF. Denoting by AC(N) the countable axiom of choice, we show in ZF+AC(N) that the closed unit ball of a uniformly convex Banach space is compact in the convex topology (an alternative to the weak…

Functional Analysis · Mathematics 2008-12-18 Marianne Morillon

In this paper we introduce FG- coupled fixed point, which is a generalization of coupled fixed point for nonlinear mappings in partially ordered complete metric spaces. We discuss existence and uniqueness theorems of FG- coupled fixed…

General Topology · Mathematics 2016-10-04 Prajisha Eacha , Shaini Pulickakunnel

The 2015 fixed point result on rs-relational metric spaces due to Alam and Imdad [J. Fixed Point Th. Appl., 17 (2015), 693-702] is equivalent with the classical Banach Contraction Principle [Fund. Math., 3 (1922), 133-181]. This is also…

General Topology · Mathematics 2026-04-21 Mihai Turinici

In this paper, we show that several extension of Banach contraction principle, can be easily derived from the Caristi's theorem is one of the useful generalization of Banach contraction principle in the setting of the complete metric…

Metric Geometry · Mathematics 2015-06-17 Farshid Khojasteh , Erdal Karapinar , Hassan Khandani

We introduce a new class of asymptotic contractions that employs two quasi-metrics defined directly in terms of the underlying mapping. The contraction condition compares these two quantities via a sequence of bounding functions that…

Functional Analysis · Mathematics 2026-04-20 Jie Shi

In this paper we study fixed point properties for semitopological semigroup of nonexpansive mappings on a bounded closed convex subset of a Banach space. We also study a Schauder fixed point property for a semitopological semigroup of…

Functional Analysis · Mathematics 2012-07-20 A. T. -M. Lau , Yong Zhang

In this article, we prove the existence of common fixed points for a pair of maps on a $q$-spherically complete $T_0$-ultra-quasi-metric space. The present article is a generalization, in the assymmetric setting of the paper of Rao et…

General Topology · Mathematics 2014-12-04 Collins Amburo Agyingi , Yaé Ulrich Gaba

An important consequence of the Hahn-Banach Theorem says that on any locally convex Hausdorff topological space $X$, there are sufficiently many continuous linear functionals to separate points of $X$. In the paper, we establish a `local'…

Functional Analysis · Mathematics 2018-09-07 Niushan Gao , Denny H. Leung , Foivos Xanthos

In this paper the notion of modular cone metric space is introduced and some properties of such spaces are investigated. Also we define convex modular cone metric which takes values in CR(Y) where Y is a compact Hausdorff space. Then a…

Functional Analysis · Mathematics 2013-10-15 Saeedeh Shamsi Gamchi , Mohammad Janfada , Asadollah Niknam

Following the definition of perturbed metric space, in this paper, some fixed point theorems are established for $ F $-perturbed mappings in complete perturbed metric spaces and justify the result by counter example. Finally, an application…

Metric Geometry · Mathematics 2026-04-06 Dipti Barman , T. Bag
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