English

Critical partition regular functions for compact spaces

General Topology 2026-01-21 v1

Abstract

We study ideal-based refinements of sequential compactness arising from the class FinBW(I), consisting of topological spaces in which every sequence admits a convergent subsequence indexed by a set outside a given ideal I. A central theme of this work is the existence of critical ideals whose position in the Katetov order determines the relationship between a fixed class of spaces and the corresponding FinBW(I) classes. Building on earlier results characterizing several classical topological classes via such ideals, we extend this theory to a broader framework based on partition regular functions, which unifies ordinary convergence with other non-classical convergence notions such as IP- and Ramsey-type convergence. Furthermore, we investigate the existence of critical ideals associated with function classes motivated by Mazurkiewicz's theorem on uniformly convergent subsequences.

Keywords

Cite

@article{arxiv.2601.12041,
  title  = {Critical partition regular functions for compact spaces},
  author = {Rafał Filipów and Małgorzata Kowalczuk and Hubert Książek and Adam Kwela and Grzegorz Ucal},
  journal= {arXiv preprint arXiv:2601.12041},
  year   = {2026}
}
R2 v1 2026-07-01T09:08:54.447Z