Searcharxiv⌕ Search

arXiv subjects

Małgorzata Kowalczuk

Publications and source records attributed to Małgorzata Kowalczuk.

2 recordsLinked to original sources

Critical partition regular functions for compact spaces

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.

math.GN↗

Critical ideals for compact spaces

For each countable ordinal $α$, we introduce an ideal $conv_α$ and use it to characterize the class of all compact countable spaces which are homeomorphic to the space $ω^α\cdot n+1$ with the order topology. The characterization is expressed in terms of finding a convergent subsequence defined on a set not belonging to $conv_α$.

math.GN↗