On the lattice of weak topologies on the bicyclic monoid with adjoined zero

A Hausdorff topology \(\tau\) on the bicyclic monoid with adjoined zero \(\mathcal{C}^0\) is called weak if it is contained in the coarsest inverse semigroup topology on \(\mathcal{C}^0\). We show that the lattice \(\mathcal{W}\) of all weak shift-continuous topologies on \(\mathcal{C}^0\) is isomor...

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Date:2020
Main Authors: Bardyla, S., Gutik, O.
Format: Article
Language:English
Published: Lugansk National Taras Shevchenko University 2020
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Online Access:https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1459
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Journal Title:Algebra and Discrete Mathematics

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Algebra and Discrete Mathematics
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author Bardyla, S.
Gutik, O.
author_facet Bardyla, S.
Gutik, O.
author_sort Bardyla, S.
baseUrl_str
collection OJS
datestamp_date 2021-01-05T07:11:25Z
description A Hausdorff topology \(\tau\) on the bicyclic monoid with adjoined zero \(\mathcal{C}^0\) is called weak if it is contained in the coarsest inverse semigroup topology on \(\mathcal{C}^0\). We show that the lattice \(\mathcal{W}\) of all weak shift-continuous topologies on \(\mathcal{C}^0\) is isomorphic to the lattice \(\mathcal{SIF}^1{\times}\mathcal{SIF}^1\) where \(\mathcal{SIF}^1\) is the set of all shift-invariant filters on \(\omega\) with an attached element \(1\) endowed with the following partial order: \(\mathcal{F}\leq \mathcal{G}\) if and only if \(\mathcal{G}=1\) or \(\mathcal{F}\subset \mathcal{G}\). Also, we investigate cardinal characteristics of the lattice \(\mathcal{W}\). In particular, we prove that \(\mathcal{W}\) contains an antichain of cardinality \(2^{\mathfrak{c}}\) and a well-ordered chain of cardinality \(\mathfrak{c}\). Moreover, there exists a well-ordered chain of first-countable weak topologies of order type \(\mathfrak{t}\).
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spelling admjournalluguniveduua-article-14592021-01-05T07:11:25Z On the lattice of weak topologies on the bicyclic monoid with adjoined zero Bardyla, S. Gutik, O. lattice of topologies, bicyclic monoid, shift-continuous topology 22A15, 06B23 A Hausdorff topology \(\tau\) on the bicyclic monoid with adjoined zero \(\mathcal{C}^0\) is called weak if it is contained in the coarsest inverse semigroup topology on \(\mathcal{C}^0\). We show that the lattice \(\mathcal{W}\) of all weak shift-continuous topologies on \(\mathcal{C}^0\) is isomorphic to the lattice \(\mathcal{SIF}^1{\times}\mathcal{SIF}^1\) where \(\mathcal{SIF}^1\) is the set of all shift-invariant filters on \(\omega\) with an attached element \(1\) endowed with the following partial order: \(\mathcal{F}\leq \mathcal{G}\) if and only if \(\mathcal{G}=1\) or \(\mathcal{F}\subset \mathcal{G}\). Also, we investigate cardinal characteristics of the lattice \(\mathcal{W}\). In particular, we prove that \(\mathcal{W}\) contains an antichain of cardinality \(2^{\mathfrak{c}}\) and a well-ordered chain of cardinality \(\mathfrak{c}\). Moreover, there exists a well-ordered chain of first-countable weak topologies of order type \(\mathfrak{t}\). Lugansk National Taras Shevchenko University Austrian Science Fund FWF (Grant I 3709 N35) 2020-12-30 Article Article Peer-reviewed Article application/pdf https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1459 10.12958/adm1459 Algebra and Discrete Mathematics; Vol 30, No 1 (2020) 2415-721X 1726-3255 en https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1459/pdf https://admjournal.luguniv.edu.ua/index.php/adm/article/downloadSuppFile/1459/585 Copyright (c) 2020 Algebra and Discrete Mathematics
spellingShingle lattice of topologies
bicyclic monoid
shift-continuous topology
22A15
06B23
Bardyla, S.
Gutik, O.
On the lattice of weak topologies on the bicyclic monoid with adjoined zero
title On the lattice of weak topologies on the bicyclic monoid with adjoined zero
title_full On the lattice of weak topologies on the bicyclic monoid with adjoined zero
title_fullStr On the lattice of weak topologies on the bicyclic monoid with adjoined zero
title_full_unstemmed On the lattice of weak topologies on the bicyclic monoid with adjoined zero
title_short On the lattice of weak topologies on the bicyclic monoid with adjoined zero
title_sort on the lattice of weak topologies on the bicyclic monoid with adjoined zero
topic lattice of topologies
bicyclic monoid
shift-continuous topology
22A15
06B23
topic_facet lattice of topologies
bicyclic monoid
shift-continuous topology
22A15
06B23
url https://admjournal.luguniv.edu.ua/index.php/adm/article/view/1459
work_keys_str_mv AT bardylas onthelatticeofweaktopologiesonthebicyclicmonoidwithadjoinedzero
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