English
Related papers

Related papers: Measures of Weak Compactness and Fixed Point Theor…

200 papers

In this paper, we introduce the notion of topologically Banach contraction mapping defined on an arbitrary topological space X with the help of a continuous function $g:X\times X\rightarrow \mathbb{R}$ and investigate the existence of fixed…

General Topology · Mathematics 2020-07-22 Sumit Som , Supriti Laha , Lakshmi Kanta Dey

With every locally compact group $G$, one can associate several interesting bi-invariant subspaces $X(G)$ of the weakly almost periodic functions $\mathrm{WAP}(G)$ on $G$, each of which captures parts of the representation theory of $G$.…

Functional Analysis · Mathematics 2022-03-30 Tim de Laat , Safoura Zadeh

Properties of first-order Sobolev-type spaces on abstract metric measure spaces, so-called Newtonian spaces, based on quasi-Banach function lattices are investigated. The set of all weak upper gradients of a Newtonian function is of…

Functional Analysis · Mathematics 2013-08-14 Lukáš Malý

We introduce the metric space valued in partially ordered groups, and define the convergence of sequences and the multi-valued weak contractions, etc., on the space. We then establish endpoint theorems for the defined maps. Our…

Functional Analysis · Mathematics 2014-06-03 Congdian Cheng

We prove some results on weakly almost square Banach spaces and their relatives. On the one hand, we discuss weak almost squareness in the setting of Banach function spaces. More precisely, let $(\Omega,\Sigma)$ be a measurable space, let…

Functional Analysis · Mathematics 2023-01-20 José Rodríguez , Abraham Rueda Zoca

We recall the Chernoff-Marsden definition of weak symplectic structure and give a rigorous treatment of the functional analysis and geometry of weak symplectic Banach spaces. We define the Maslov index of a continuous path of Fredholm pairs…

Differential Geometry · Mathematics 2013-12-10 Bernhelm Booss-Bavnbek , Chaofeng Zhu

We show that the direct sum of Banach spaces $X_{1},..., X_{r}$ with a strictly monotone norm has the weak fixed point property for nonexpansive mappings whenever $M(X_{i})>1$ for each $i=1,...,r$. In particular, $(X_{1} \oplus ... \oplus…

Functional Analysis · Mathematics 2015-11-24 Andrzej Wiśnicki

We prove the following results: (i) Every absolutely weakly compact set in a Banach lattice is absolutely weakly sequentially compact. (ii) The converse of (i) holds if $E$ is separable or $B_{E^{**}}$ is absolutely weak$^*$ compact. (iii)…

Functional Analysis · Mathematics 2023-04-18 Geraldo Botelho , José Lucas P. Luiz , Vinicius C. C. Miranda

In this paper, we establish a Minkowski-type inequality for weak Lebesgue space, which allows us to obtain a characterization of relative compactness in these spaces. Furthermore, we are the first to investigate the compactness results of…

Functional Analysis · Mathematics 2023-09-20 Dinghuai Wang , Xi Hu , Shuai Qi

Several characterizations of weak cotype 2 and weak Hilbert spaces are given in terms of basis constants and other structural invariants of Banach spaces. For finite-dimensional spaces, characterizations depending on subspaces of fixed…

Functional Analysis · Mathematics 2009-09-25 P. Mankiewicz , Nicole Tomczak-Jaegermann

The purpose of this article is to prove existence of mass minimizing integral currents with prescribed possibly non-compact boundary in all dual Banach spaces and furthermore in certain spaces without linear structure, such as injective…

Differential Geometry · Mathematics 2012-03-26 Stefan Wenger

Rectangular TVS-cone metric spaces are introduced and Kannan's fixed point theorem is proved in these spaces. Two approaches are followed for the proof. At first we prove the theorem by a direct method using the structure of the space…

General Topology · Mathematics 2011-02-11 Thabet Abdeljawad , Duran Türkoğlu

We present a constructive proof of Tychonoff's fixed point theorem in a locally convex space for sequentially locally non-constant functions, As a corollary to this theorem we also present Schauder's fixed point theorem in a Banach space…

Logic · Mathematics 2011-05-19 Yasuhito Tanaka

We show the existence of Lipschitz-free spaces verifying the Point of Continuity Property with arbitrarily high weak-fragmentability index. For this purpose, we use a generalized construction of the countably branching diamond graphs. As a…

Functional Analysis · Mathematics 2025-04-25 Estelle Basset

We introduce "weakly chained spaces", which need not be locally connected or path connected, but for which one has a reasonable notion of generalized fundamental group and associated generalized universal cover. We show that in the compact…

Algebraic Topology · Mathematics 2021-03-16 Conrad Plaut

This paper is devoted to the study of the relatively compact sets in Quasi-Banach function spaces, providing an important improvement of the known results. As an application, we take the final step in establishing a relative compactness…

Classical Analysis and ODEs · Mathematics 2020-06-24 Weichao Guo , Guoping Zhao

The aim of this paper is to prove the existence of common fixed points for a pair of weakly compatible selfmaps satisfying weakly contractive condition and property (E. A). In this context, first we modify Beg and Abbas theorem (\cite{Beg},…

Functional Analysis · Mathematics 2025-08-05 G. V. R. Babu , Alemayehu G. Negash

In this article, we introduce the concept of weakly uniquely stationary representations. This framework enables us to investigate the complementability of closed subspaces within the context of continuous cohomology with coeffcients in…

Functional Analysis · Mathematics 2025-07-14 Mario Klisse

We prove that if X is an infinite-dimensional Banach space with C^p smooth partitions of unity, then X and X\K are C^p diffeomorphic, for every weakly compact subset K of X.

Functional Analysis · Mathematics 2007-05-23 Daniel Azagra , Alejandro Montesinos

In this present article, we etablish some existence results of $\varphi-$fixed point of a mapping in a $C^{\ast}$-algebra valued metric spaces and we deduce some fixed point theorems in $C^{\ast}$-algebra valued partial metric spaces.…

Operator Algebras · Mathematics 2022-04-20 Hafida Massit , Mohamed Rossafi