{ "id": "2308.09557", "version": "v1", "published": "2023-08-18T13:40:51.000Z", "updated": "2023-08-18T13:40:51.000Z", "title": "Spaces not distinguishing ideal pointwise and $σ$-uniform convergence", "authors": [ "Rafał Filipów", "Adam Kwela" ], "categories": [ "math.GN" ], "abstract": "We examine topological spaces not distinguishing ideal pointwise and ideal $\\sigma$-uniform convergence of sequences of real-valued continuous functions defined on them. For instance, we introduce a purely combinatorial cardinal characteristic (a sort of the bounding number $\\mathfrak{b}$) and prove that it describes the minimal cardinality of topological spaces which distinguish ideal pointwise and ideal $\\sigma$-uniform convergence. Moreover, we provide examples of topological spaces (focusing on subsets of reals) that do or do not distinguish the considered convergences. Since similar investigations for ideal quasi-normal convergence instead of ideal $\\sigma$-uniform convergence have been performed in literature, we also study spaces not distinguishing ideal quasi-normal and ideal $\\sigma$-uniform convergence of sequences of real-valued continuous functions defined on them.", "revisions": [ { "version": "v1", "updated": "2023-08-18T13:40:51.000Z" } ], "analyses": { "subjects": [ "54C30", "40A35", "03E17", "40A30", "26A03", "54A20", "03E35" ], "keywords": [ "uniform convergence", "distinguishing ideal pointwise", "topological spaces", "real-valued continuous functions", "ideal quasi-normal convergence" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }