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In this article, we work with set-valued optimization problems in locally convex topological vector spaces. We prove the equivalencies of some definitions of generalized convex maps introduced by Jeyakumar, Yang, Yang & Yang & Chen, as well…

Optimization and Control · Mathematics 2024-03-05 Renying Zeng

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

We shall generalize the concept of $z=(1-t)x\oplus ty$ to $n$ times which contains to verifying some their properties and inequalities in CAT(0) spaces. In the sequel with introducing of $\alpha$-nonexpansive mappings, we obtain some fixed…

Functional Analysis · Mathematics 2012-05-31 Mehdi Asadi , Hossein Soleimani

We adapt the definition of the Vietoris map to the framework of finite topological spaces and we prove some coincidence theorems. From them, we deduce a Lefschetz fixed point theorem for multivalued maps that improves recent results in the…

Dynamical Systems · Mathematics 2020-10-27 Pedro J. Chocano , Manuel A. Morón , Francisco R. Ruiz del Portal

In this paper provide sufficient and necessary conditions for the minimax equality for extended-valued $\Phi$-convex functions. As an application we establish sufficient and necessary conditions for the minimax equality for convex-concave…

Optimization and Control · Mathematics 2017-01-11 Monika Syga

For the minimal graph defined on a convex ring in the space form with nonnegative curvature, we obtain the regularity and the strict convexity about its level sets by the continuity method.

Analysis of PDEs · Mathematics 2016-07-21 Peihe Wang , Dekai Zhang

In this paper a generalized topological central point theorem is proved for maps of a simplex to finite-dimensional metric spaces. Similar generalizations of the Tverberg theorem are considered.

Algebraic Topology · Mathematics 2012-02-07 R. N. Karasev

Using the setting of $G$-metric spaces, common fixed point theorems for four maps satisfying the weakly commuting conditions are obtained for various generalized contractive conditions. Several examples are also presented to show the…

General Topology · Mathematics 2023-07-24 Talat Nazir , Sergei Silvestrov

For an upper semi-continuous set-valued mapping from one topological space to another and for a lower semi-continuous function defined on the product of these spaces, Berge's theorem states lower semi-continuity of the minimum of this…

General Topology · Mathematics 2012-03-08 Eugene A. Feinberg , Pavlo O. Kasyanov , Nina V. Zadoianchuk

Detecting hidden convexity is one of the tools to address nonconvex minimization problems. After giving a formal definition of hidden convexity, we introduce the notion of conditional infimum, as it will prove instrumental in detecting…

Optimization and Control · Mathematics 2021-04-13 Jean-Philippe Chancelier , Michel de Lara

We prove the existence of equilibrium states for geometric potentials in a class of piecewise weakly convex interval maps. This class includes systems with indifferent fixed points and non-Markov partitions. Under additional hypotheses we…

Dynamical Systems · Mathematics 2026-03-04 Nicolás Arévalo-Hurtado

We survey several applications of fixed point theorems in the theory of invariant subspaces. The general idea is that a fixed point theorem applied to a suitable map yields the existence of invariant subspaces for an operator on a Banach…

Operator Algebras · Mathematics 2012-10-23 Rafa Espínola , Miguel Lacruz

In this paper, we present some common fixed point theorems for a commuting pair of mappings, including a generalized nonexpansive single valued mapping and a generalized nonexpansive multivalued mapping in strictly convex Banach spaces. The…

Functional Analysis · Mathematics 2011-02-09 Ali Abkar , Mohammad Eslamian

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

A new and extensive formalism is developed for monads and galaxies in non-standard enlargements. It is shown that monads and galaxies can be manipulated using order-preserving and order-reversing set-to-set maps, and that set properties…

Logic · Mathematics 2024-06-12 Niels Charlier , Hans Vernaeve

We introduce moment maps for continuous unitary representations of general topological groups. For solvable separable locally compact groups, we prove that the closure of the image of the moment map of any representation is convex.

Representation Theory · Mathematics 2014-08-21 Daniel Beltita , Mihai Nicolae

In this paper, we study the existence of solutions for generalized vector quasi-equilibrium problems. Firstly, we prove that in the case of Banach spaces, the assumptions of continuity over correspondences can be weakened. The theoretical…

Optimization and Control · Mathematics 2016-05-12 Monica Patriche

In this paper, we introduce the new concepts of subcompatibility and subsequential continuity which are respectively weaker than occasionally weak compatibilty and reciprocal continuity. With them, we establish several common fixed point…

Functional Analysis · Mathematics 2011-05-24 Hakima Bouhadjera , Christiane Godet-Thobie

The following selection theorem is established:\\ Let $X$ be a compactum possessing a binary normal subbase $\mathcal S$ for its closed subsets. Then every set-valued $\mathcal S$-continuous map $\Phi\colon Z\to X$ with closed $\mathcal…

General Topology · Mathematics 2013-11-05 Vesko Valov

The first aim of this paper is to examine some important properties of soft metric spaces. Second is to introduce soft continuous mappings and investigate properties of soft continuous mappings. Third is to prove some fixed point theorems…

General Mathematics · Mathematics 2013-08-22 Murat I. Yazar , Cigdem Gunduz , Sadi Bayramov