English
Related papers

Related papers: Minimax theorems for set-valued maps without conti…

200 papers

For a finite and positive measure space $(\Omega,\Sigma,\mu)$ and any weakly compact convex subset of $L\sp\infty(\Omega,\Sigma,mu)$, a fixed point theorem for a class of nonexpansive self-mappings is proved. An analogous result is obtained…

Functional Analysis · Mathematics 2007-05-23 Cleon S. Barroso

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

We establish a fixed-point theorem for the face maps that consist in deleting the $i$th entry of an ordered set. Furthermore, we show that there exists random finite sets of integers that are almost invariant under such deletions.…

Group Theory · Mathematics 2026-04-01 Tom Hutchcroft , Nicolas Monod , Omer Tamuz

In this paper we prove some new fixed point theorems for multivalued mappings on orbitally complete uniform spaces.

General Topology · Mathematics 2007-05-23 Duran Turkoglu , Brian Fisher

In this paper, the existence of coincidence points and common fixed points for multivalued mappings satisfying certain graphic {\psi}-contraction contractive conditions with set-valued domain endowed with a graph, without appealing to…

General Mathematics · Mathematics 2016-06-17 Sergei Silvestrov , Talat Nazir

Finding the minimum and the minimizers of convex functions has been of primary concern in convex analysis since its conception. It is well-known that if a convex function has a minimum, then that minimum is global. The minimizers, however,…

Optimization and Control · Mathematics 2014-10-07 C. Planiden , X. Wang

Some known fixed point theorems for nonexpansive mappings in metric spaces are extended here to the case of primitive uniform spaces. The reasoning presented in the proofs seems to be a natural way to obtain other general results.

General Topology · Mathematics 2021-04-09 Lech Pasicki

Continuity of the value of the martingale optimal transport problem on the real line w.r.t. its marginals was recently established in Backhoff-Veraguas and Pammer [2] and Wiesel [21]. We present a new perspective of this result using the…

Probability · Mathematics 2021-04-23 Ariel Neufeld , Julian Sester

In this paper, we introduce the concept of quasi-point-separable topological vector spaces, which has the following important properties: 1.In general, the conditions for a topological vector space to be quasi-point-separable is not very…

Functional Analysis · Mathematics 2022-01-04 Jinlu Li

Deciding whether saddle points exist or are approximable for nonconvex-nonconcave problems is usually intractable. This paper takes a step towards understanding a broad class of nonconvex-nonconcave minimax problems that do remain…

Optimization and Control · Mathematics 2023-05-30 Peiyuan Zhang , Jingzhao Zhang , Suvrit Sra

We present a general fixed point theorem which can be seen as the quintessence of the principles of proof for Banach's Fixed Point Theorem, ultrametric and certain topological fixed point theorems. It works in a minimal setting, not…

Commutative Algebra · Mathematics 2013-04-02 Katarzyna Kuhlmann , Franz-Viktor Kuhlmann

In this paper, we prove the existence of fixed points of mappings satisfying the condition (Da), a kind of generalized nonexpansive mappings, on a weakly compact convex subset in a Banach space satisfying Opial's condition. And we use…

Functional Analysis · Mathematics 2020-07-07 Chang Il Rim , Jong Gyong Kim

In this paper, we prove first that the iterates of a mean nonexpansive map defined on a weakly compact, convex set converge weakly to a fixed point in the presence of Opial's property and asymptotic regularity at a point. Next, we prove the…

Functional Analysis · Mathematics 2016-11-30 Torrey M. Gallagher

In this paper, we introduce the concepts of weaknorm, quasi-weaknorm on real vector spaces. By these concepts, we introduce the concept of quasi-locally convex topological vector spaces, which include locally convex topological vector…

Functional Analysis · Mathematics 2020-01-01 Jinlu Li

We introduce a new type of mappings in metric spaces which are three-point analogue of the well-known Kannan type mappings and call them generalized Kannan type mappings. It is shown that in general case such mappings are discontinuous but…

General Topology · Mathematics 2025-01-06 Evgeniy Petrov , Ravindra K. Bisht

In this note we propose a min-max theory for embedded hypersurfaces with a fixed boundary and apply it to prove several theorems about the existence of embedded minimal hypersurfaces with a given boundary. A simpler variant of these…

Analysis of PDEs · Mathematics 2017-05-19 Camillo De Lellis , Jusuf Ramic

We study the class of compact convex subsets of a topological vector space which admits a strictly convex and lower semicontinuous function. We prove that such a compact set is embeddable in a strictly convex dual Banach space endowed with…

Functional Analysis · Mathematics 2015-10-28 L. García-Lirola , J. Orihuela , M. Raja

The main purpose of this paper is to find the fixed point in such cases where existing literature remain silent. In this paper we introduce partial completeness, a new type of contraction and many other definitions. Using this approach the…

Functional Analysis · Mathematics 2018-03-23 Tawseef Rashid , Qamrul Haque Khan

Here is one of the results obtained in this paper: Let $X, Y$ be two convex sets each in a real vector space, let $J:X\times Y\to {\bf R}$ be convex and without global minima in $X$ and concave in $Y$, and let $\Phi:X\to {\bf R}$ be…

Optimization and Control · Mathematics 2019-09-19 Biagio Ricceri

In this paper, we introduce the concepts of m-quasiconvex, originally m-quasiconvex,and generalized m-quasiconvex functionals on topological vector spaces. Then we extend the concept of point separable topological vector spaces (by the…

Functional Analysis · Mathematics 2020-12-07 Jinlu Li