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In this paper, we consider Mean Field Games in the presence of common noise relaxing the usual independence assumption of individual random noise. We assume a simple linear model with terminal cost satisfying a convexity and a weak…

Probability · Mathematics 2016-07-05 Saran Ahuja

We prove fixed point theorems in a space with a distance function that takes values in a partially ordered monoid. On the one hand, such an approach allows one to generalize some fixed point theorems in a broad class of spaces, including…

Functional Analysis · Mathematics 2026-03-24 Vladyslav Babenko , Vira Babenko , Oleg Kovalenko

The aim of this paper is to generalize some fixed point theorems in the class of convex contraction of order $m$ on a complete suprametric space. Then, we will prove that the class of convex contraction of order m is strong enough to…

General Mathematics · Mathematics 2026-05-11 Nicola Fabiano , Sedigheh Barootkoob , Hossein Lakzian

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 give a simple proof of the Baillon-Haddad theorem for convex functions defined on open and convex subsets of Hilbert spaces. We also state some generalizations and limitations. In particular, we discuss equivalent characterizations of…

Functional Analysis · Mathematics 2022-04-04 Daniel Wachsmuth , Gerd Wachsmuth

Suppose that $Q$ is a weak$^{\ast }$ compact convex subset of a dual Banach space with the Radon-Nikod\'{y}m property. We show that if $(S,Q)$ is a nonexpansive and norm-distal dynamical system, then there is a fixed point of $S$ in $Q$ and…

Dynamical Systems · Mathematics 2022-01-03 Andrzej Wiśnicki

We present a fixed point theorem for a class of (potentially) non-monotonic functions over specially structured complete lattices. The theorem has as a special case the Knaster-Tarski fixed point theorem when restricted to the case of…

Logic in Computer Science · Computer Science 2015-02-10 Zoltán Ésik , Panos Rondogiannis

Let $\mu$ be a probability measure on a separable Banach space $X$. A subset $U\subset X$ is $\mu$-continuous if $\mu(\partial U)=0$. In the paper the $\mu$-continuity and uniform $\mu$-continuity of convex bodies in $X$, especially of…

Functional Analysis · Mathematics 2012-09-03 Anatolij Plichko

In this paper, we first provide a simple variational proof of the existence of Nash equilibrium in Hilbert spaces by using optimality conditions in convex minimization and Schauder's fixed-point theorem. Then applications of convex analysis…

Optimization and Control · Mathematics 2024-08-27 Nguyen Xuan Duy Bao , Boris Mordukhovich , Nguyen Mau Nam

We prove that every Banach space containing a subspace isomorphic to $\co$ fails the fixed point property. The proof is based on an amalgamation approach involving a suitable combination of known results and techniques, including James's…

Functional Analysis · Mathematics 2018-08-15 Cleon S. Barroso

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

In this article, we extend several relation-theoretic notions to topological spaces. We introduce relation preserving contraction mapping into topological spaces and utilize the same to extend Banach contraction principle in topological…

General Mathematics · Mathematics 2025-09-16 Md Hasanuzzaman , Abhishikta Das , Sumit Som

In this paper, we investigate the existence of fixed points for asymptotically nonexpansive mappings with center 0 defined on closed convex subsets of various Banach spaces. Three applications are given. Firstly, we prove that our results…

Functional Analysis · Mathematics 2024-05-14 Abdelkader Dehici , Sami Atailia , Najeh Redjel

The aim of this paper is to prove a fixed point theorem on a generalised cone metric spaces for maps satisfying general contractive type conditions.

Classical Analysis and ODEs · Mathematics 2016-10-04 Sudip Kumar Pal , Manojit Maity

We prove that all isometric actions of higher rank simple Lie groups and their lattices on arbitrary uniformly convex Banach spaces have a fixed point. This vastly generalises a recent breakthrough of Oppenheim. Combined with earlier work…

Group Theory · Mathematics 2023-03-09 Tim de Laat , Mikael de la Salle

Non-convex functions that yet satisfy a condition of uniform convexity for non-close points can arise in discrete constructions. We prove that this sort of discrete uniform convexity is inherited by the convex envelope, which is the key to…

Functional Analysis · Mathematics 2021-05-12 Guillaume Grelier , Matías Raja

In this work, using a new geometrical approach we study to the existence of the fixed-point of mappings that independence of the smoothness, and also of their single-values or multi-values. This work proved the theorems that generalize in…

Analysis of PDEs · Mathematics 2022-03-22 Kamal N. Soltanov

We study the existence of fixed points for continuous maps $f$ from an $n$-ball $X$ in $\mathbb R^n$ to $\mathbb R^n$ with $n\geq 1$. We show that $f$ has a fixed point if, for some absolute retract $Y\subset\partial X$, $f(Y)\subset X$ and…

Dynamical Systems · Mathematics 2024-04-09 Jiehua Mai , Enhui Shi , Kesong Yan , Fanping Zeng

We show that the standard approach of minimal invariant sets, which applies Zorn's Lemma and is used to prove fixed point theorems for non-expansive mappings in Banach spaces can be applied without any reference to the full Axiom of Choice…

Logic · Mathematics 2017-01-16 Vassilios Gregoriades

We prove a sharp stability result concerning how close homothetic sets attaining near-equality in the Brunn-Minkowski inequality are to being convex. In particular, resolving a conjecture of Figalli and Jerison, we show there are universal…

Metric Geometry · Mathematics 2020-04-17 Peter van Hintum , Hunter Spink , Marius Tiba