Normal structure in modulated topological vector spaces

Wojciech M Kozlowski

Commentationes Mathematicae, Tome 60 (2020) no. 1-2, pp. 1-11.

Résumé

Following the author’s recent paper \emph{On modulated topological vector spaces and applications}, Bull. Aust. Math. Soc. (2020), we discuss a notion of modulated topological vector spaces, that generalise, among others, Banach spaces and modular function spaces. The interest in modulars reflects the fact that the notions of ``norm like'' but ``non-euclidean'' (i.e., possibly without the triangle property and non-necessarily homogenous) constructs to measure a level of proximity between complex objects have been used extensively in statistics and applied in many empirical scientific projects requiring an objective differentiation between several classes of objects, efficiently applied in many modern clustering and Artificial Intelligence (AI) related computer algorithms. As an example of application, we prove some results, which extend fixed point theorems from the above mentioned paper, by moving from the setting of admissible sets to a simpler and more general setup, which covers also closed bounded sets. The theory of modulated topological vector spaces provides a very minimalistic framework, where powerful geometrical, fixed point, approximation and optimisation theorems are valid under a bare minimum of assumptions.

Détail

DOI : 10.14708/cm.v60i1-2.6529

Classification : 47H09, 46B20, 47H10, 47E10
Mots-clés : Topological vector spaces, Banach spaces, modular spaces, modular function spaces, fixed points, nonexpansive mappings, normal structure