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...

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Bibliographic Details
Main Authors: Tilahun Bayih, Themba Dube, Oghenetega Ighedo
Format: Article
Language:English
Published: Universitat Politècnica de València 2021-04-01
Series:Applied General Topology
Subjects:
Online Access:https://polipapers.upv.es/index.php/AGT/article/view/14915
Description
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.
ISSN:1576-9402
1989-4147