Completeness properties in a broader context
We give a characterization of cofinal local compactness for all totally dis- connected cosmic spaces. As an application of this result we prove that an ultrafilter ξ ∈ βω\ωis a P -point in βω\ω if and only if the space ω ∪ {ξ} is cofinally locally compact. We also show that a subspace X of an ordinal is cofinally locally compact if and only if ext(X ) ≤ ω and every closed countable subspace of X is locally compact. It is established that, for any GO space X , if is Čech-complete (metrizable) for any discrete set D ⊂ X × X , then X is Čech-complete (or metrizable respectively). Besides, it is proved that discrete Čech-completeness of a metric space implies its Baire property. Our results provide an answer to a published open question.
Authors
- Vladimir V. Tkachuk
- Joel Alberto Aguilar-Velázquez
Institutions
- Universidad Autónoma Metropolitana (MX)
Publication Details
- Journal
- Quaestiones Mathematicae
- Published
- 2026-07-24
- DOI
- https://doi.org/10.2989/16073606.2026.2700017
- Primary Topic
- Advanced Topology and Set Theory
- Type
- article
- Field-Weighted Citation Impact
- 0.00