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In this paper, first we have established two sets of sufficient conditions for a mapping to have unique fixed point in a intuitionistic fuzzy metric space and then we have redefined the contraction mapping in a intuitionistic fuzzy metric…

General Mathematics · Mathematics 2010-11-09 T. K. Samanta , Sumit Mohinta , Iqbal H. Jebril

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

As an application of Brouwer's fixed-point theorem we prove that a continuously differentiable convex function with gradient of constant norm is an affine mapping. It is a first-order characterization of affine mappings among continuously…

Classical Analysis and ODEs · Mathematics 2025-11-10 Csaba Vincze

Our aim in this paper is to present results of existence of fixed points for continuous operators in Banach spaces using measure of noncompactness under an integral condition. This results are generalization of results given by A. Aghajania…

Functional Analysis · Mathematics 2015-07-02 Vatan Karakaya , Bouzara Nour El Houda , Kadri Dogan , Yunus Atalan

In this paper, first some results of [5] are extended for subadditive separating maps between C(X;E) and C(Y;E), such that E is a unital Banach algebra. Then we give some conditions under which a strongly subadditive map has a unique fixed…

Functional Analysis · Mathematics 2015-06-02 Yousef Estaremi , Bahman Moeini

In the setting of CAT(k) spaces, common fixed point iterations built from prox mappings (e.g. prox-prox, Krasnoselsky-Mann relaxations, nonlinear projected-gradients) converge locally linearly under the assumption of linear metric…

Optimization and Control · Mathematics 2021-12-13 Florian Lauster , D. Russell Luke

In this paper, the Pazy's Fixed Point Theorems of monotone $\alpha-$nonexpansive mapping $T$ are proved in a uniformly convex Banach space $E$ with the partial order "$\leq$". That is, we obtain that the fixed point set of $T$ with respect…

Functional Analysis · Mathematics 2016-06-28 Yisheng Song , Rudong Chen

In this article, we introduce a four-point analogue of Banach-type, Kannan-type, and Chatterjea-type contractions, and examine their properties. We establish sufficient conditions under which these mappings achieve fixed points in a…

Functional Analysis · Mathematics 2024-07-11 Anish Banerjee , Pratikshan Mondal , Lakshmi Kanta Dey

Generalization of Lyapunov convexity theorem is proved for vector measure with values in Banach spaces with unconditional bases, which are q-concave for some $q<\infty.$

Functional Analysis · Mathematics 2013-10-18 Anna Novikova

The concept of adjusted sublevel set for a quasiconvex function was introduced in \cite{AuHa05} and the local existence of a norm-to-weak$^*$ upper semicontinuous base-valued submap of the normal operator associated to the adjusted sublevel…

Optimization and Control · Mathematics 2023-01-31 Marco Castellani , Massimiliano Giuli

Banach's fixed point theorem in linear n-normed space is being developed. Also, we present several theorems on fixed points in linear n-normed space.

Metric Geometry · Mathematics 2022-10-17 Prasenjit Ghosh , T. K. Samanta

In this paper, two main results concerning uniformly continuous retractions are proved. First, an $\alpha$-H\"older retraction from any separable Banach space onto a compact convex subset whose closed linear span is the whole space is…

Functional Analysis · Mathematics 2022-05-26 Rubén Medina

We establish a simple and powerful lemma that provides a criterion for sequences in metric spaces to be Cauchy. Using the lemma, it is then easily verified that the Picard iterates $\{T^nx\}$, where $T$ is a contraction or asymptotic…

General Topology · Mathematics 2016-04-06 Mortaza Abtahi

Weintroduce a new class of mappings called cyclic p-$\phi$-contraction mappings and investigate the existence and uniqueness of fixed point for such mappings defined on metric spaces, uniformly convex Banach spaces, or reflex ive Banach…

Functional Analysis · Mathematics 2026-02-19 Seyyed Mohammad Sadegh Nabavi Sales

In this paper, we deal with a notion of Banach space-valued mappings defined on a set consisting of finite graphs with uniformly bounded vertex degree. These functions will be endowed with certain boundedness and additivity criteria. We…

Combinatorics · Mathematics 2015-01-14 Felix Pogorzelski

We introduce the class of $\alpha$-firmly nonexpansive and quasi $\alpha$-firmly nonexpansive operators on $r$-uniformly convex Banach spaces. This extends the existing notion from Hilbert spaces, where $\alpha$-firmly nonexpansive…

Functional Analysis · Mathematics 2025-03-11 Arian Bërdëllima , Gabriele Steidl

In this paper, we study the existence of fixed points for mappings defined on complete (compact) metric space (X, d) satisfying a general contractive (contraction) inequality depended on another function. These conditions are analogous to…

Functional Analysis · Mathematics 2009-03-10 A. Beiranvand , S. Moradi , M. Omid , H. Pazandeh

In this paper we present a systematic study of regular sequences of quasi-nonexpansive operators in Hilbert space. We are interested, in particular, in weakly, boundedly and linearly regular sequences of operators. We show that the type of…

Optimization and Control · Mathematics 2018-02-13 Andrzej Cegielski , Simeon Reich , Rafał Zalas

In the present paper, the following convexity principle is proved: any closed convex multifunction, which is metrically regular in a certain uniform sense near a given point, carries small balls centered at that point to convex sets, even…

Optimization and Control · Mathematics 2015-04-13 Amos Uderzo

Any maximal monotone operator can be characterized by a convex function. The family of such convex functions is invariant under a transformation connected with the Fenchel-Legendre conjugation. We prove that there exist a convex…

Functional Analysis · Mathematics 2008-03-11 B. F. Svaiter