On the Menger and almost Menger properties in locales
The Menger and the almost Menger properties are extended to locales. Regarding the former, the extension is conservative (meaning that a space is Menger if and only if it is Menger as a locale), and the latter is conservative for sober TD-spaces. Non-spatial Menger (and hence almost Menger) locales...
Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
Universitat Politècnica de València
2021-04-01
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Series: | Applied General Topology |
Subjects: | |
Online Access: | https://polipapers.upv.es/index.php/AGT/article/view/14915 |
Summary: | The Menger and the almost Menger properties are extended to locales. Regarding the former, the extension is conservative (meaning that a space is Menger if and only if it is Menger as a locale), and the latter is conservative for sober TD-spaces. Non-spatial Menger (and hence almost Menger) locales do exist, so that the extensions genuinely transcend the topological notions. We also consider projectively Menger locales, and show that, as in spaces, a locale is Menger precisely when it is Lindelöf and projectively Menger. Transference of these properties along localic maps (via direct image or pullback) is considered. |
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ISSN: | 1576-9402 1989-4147 |