Countable Tightness Is Not Discretely Reflexive in σ-Compact Spaces

Open Access
Authors
Publication date 04-2025
Journal Acta mathematica Hungarica
Volume | Issue number 175 | 2
Pages (from-to) 543-549
Organisations
  • Faculty of Science (FNWI) - Korteweg-de Vries Institute for Mathematics (KdVI)
Abstract Answering a question raised by V.V. Tkachuk in [10], we present several examples of σ-compact spaces, some only consistent and some in ZFC, that are not countably tight but in which the closure of any discrete subset is countably tight. In fact, in some of our examples the closures of all discrete subsets are even first countable.
Document type Article
Language English
Published at https://doi.org/10.1007/s10474-025-01521-7
Other links https://www.scopus.com/pages/publications/105001479170
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