English

On (ultra-) completeness numbers and (pseudo-) paving numbers

General Topology 2020-01-01 v1

Abstract

We study the completeness and ultracompleteness numbers of a convergence space. In the case of a completely regular topological space, the completeness number is countable if and only if the space is Cˇ\v{C}ech-complete, and the ultracompleteness number is countable if and only if the space is ultracomplete. We show that the completeness number of a space is equal to the pseudopaving number of the upper Kuratowski convergence on the space of its closed subsets, at \emptyset. Similarly, the ultracocompleteness number of a space is equal to the paving number of the upper Kuratowski convergence on the space of its closed subsets, at \emptyset.

Keywords

Cite

@article{arxiv.1811.04325,
  title  = {On (ultra-) completeness numbers and (pseudo-) paving numbers},
  author = {Frédéric Mynard},
  journal= {arXiv preprint arXiv:1811.04325},
  year   = {2020}
}

Comments

17 pages

R2 v1 2026-06-23T05:11:36.961Z