English
Related papers

Related papers: Fixed points, saddle points and universality

200 papers

We give a characterization of completely regular topological spaces. Applying some recent results for supinf problems in completely regular topological spaces we establish a variational principle for saddle points. Well-posedness of saddle…

Optimization and Control · Mathematics 2024-08-05 D. Kamburova , R. Marinov , N. Zlateva

The topic of fixed points in digital metric spaces has drawn yet more publications with assertions that are incorrect, incorrectly proven, trivial, or incoherently stated. We discuss publications with bad assertions concerning fixed points…

Geometric Topology · Mathematics 2025-12-19 Laurence Boxer

Several machine learning models are defined for inputs of any size, such as graphs with different numbers of nodes and point clouds containing varying numbers of points. The universality properties of such any-dimensional models remain…

Machine Learning · Computer Science 2026-05-25 Shengtai Yao , Eitan Levin , Mateo Díaz

Turing machines and spin models share a notion of universality according to which some simulate all others. Is there a theory of universality that captures this notion? We set up a categorical framework for universality which includes as…

Computational Complexity · Computer Science 2024-09-04 Tomáš Gonda , Tobias Reinhart , Sebastian Stengele , Gemma De les Coves

The topic of fixed points in digital metric spaces continues to draw publications with assertions that are incorrect, incorrectly proven, trivial, or incoherently stated. We continue the work of our earlier papers that discuss publications…

Geometric Topology · Mathematics 2025-04-08 Laurence Boxer

We discuss published assertions concerning fixed points in digital metric spaces that are incorrect or incorrectly proven, or reduce to triviality.

Geometric Topology · Mathematics 2022-04-06 Laurence Boxer

Our main aim in this paper is to introduce a general concept of multidimensional fixed point of a mapping in spaces with distance and establish various multidimensional fixed point results. This new concept simplifies the similar notion…

General Mathematics · Mathematics 2017-01-04 Mitrofan M. Choban , Vasile Berinde

The paper discusses the conditions for the existence of fixed points of multivalued mappings that are not based on the linear structure of the set. The descriptions for the sets of fixed points for mappings with closed graph in compact…

General Topology · Mathematics 2016-02-23 Dmitrii Serkov

Fixed points for scalar theories in $4-\varepsilon$, $6-\varepsilon$ and $3-\varepsilon$ dimensions are discussed. It is shown how a large range of known fixed points for the four dimensional case can be obtained by using a general…

High Energy Physics - Theory · Physics 2019-04-11 Hugh Osborn , Andreas Stergiou

We reconsider a well known problem of quantum theory, i.e. the so called measurement (or macro-objectification) problem, and we rederive the fact that it gives rise to serious problems of interpretation. The novelty of our approach derives…

Quantum Physics · Physics 2009-11-06 Angelo Bassi , GianCarlo Ghirardi

In this paper, considering a wider class of simulation functions some fixed point results for multivalued mappings in $\alpha$-complete metric spaces have been presented. Results obtained in this paper extend and generalize some well-known…

General Mathematics · Mathematics 2018-01-17 Deepesh Kumar Patel

A topological space has the fixed point property if every continuous self-map of that space has at least one fixed point. We demonstrate that there are serious restraints imposed by the requirement that there be a choice of fixed points…

General Topology · Mathematics 2015-10-20 Markus Szymik

This paper continues a series discussing flaws in published assertions concerning fixed points in digital metric spaces.

Geometric Topology · Mathematics 2023-07-21 Laurence Boxer

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 work some aspects of models with universal extra dimensions are studied. In particular, in the case of models with one universal extra dimension their phenomenology is investigated and used to extract bounds on the size of the extra…

High Energy Physics - Phenomenology · Physics 2007-05-23 Josep F. Oliver

This paper continues a series discussing flaws in published assertions concerning fixed points in digital images.

Geometric Topology · Mathematics 2023-09-11 Laurence Boxer

I now agree with conclusion of author that there is a problem with unitarity in discussed models.

High Energy Physics - Theory · Physics 2008-02-03 Paul Federbush

This paper revisits the well-studied fixed point problem from a unified viewpoint of mathematical modeling and canonical duality theory, i.e. the original problem is first reformulated as a nonconvex optimization problem, its well-posedness…

Optimization and Control · Mathematics 2018-01-29 Ning Ruan , David Yang Gao

We obtain new results on the existence and multiplicity of fixed points of Hammerstein equations in very general cones. In order to achieve this, we combine a new formulation of cones in terms of continuous functionals with fixed point…

Classical Analysis and ODEs · Mathematics 2016-11-09 Rubén Figueroa , F. Adrián F. Tojo

Inverse limits, unlike direct limits, can in general be void, [1]. The existence of fixed points for arbitrary mappings $T : X \longrightarrow X$ is conjectured to be equivalent with the fact that related direct limits of all finite…

General Mathematics · Mathematics 2007-09-05 Elemer E Rosinger
‹ Prev 1 2 3 10 Next ›