Weak Frobenius monads and Frobenius bimodules

As observed by  Eilenberg and  Moore (1965), for a monad \(F\) with right adjoint comonad \(G\) on any category \(\mathbb{A}\),  the category of unital \(F\)-modules \(\mathbb{A}_F\) is isomorphic to the category of counital \(G\)-comodules \(\mathbb{A}^G\). The monad \(F\) is Frobenius provided we...

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Date:2016
Main Author: Wisbauer, Robert
Format: Article
Language:English
Published: Lugansk National Taras Shevchenko University 2016
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Online Access:https://admjournal.luguniv.edu.ua/index.php/adm/article/view/133
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Journal Title:Algebra and Discrete Mathematics

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Algebra and Discrete Mathematics
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author Wisbauer, Robert
author_facet Wisbauer, Robert
author_sort Wisbauer, Robert
baseUrl_str
collection OJS
datestamp_date 2016-07-12T10:09:40Z
description As observed by  Eilenberg and  Moore (1965), for a monad \(F\) with right adjoint comonad \(G\) on any category \(\mathbb{A}\),  the category of unital \(F\)-modules \(\mathbb{A}_F\) is isomorphic to the category of counital \(G\)-comodules \(\mathbb{A}^G\). The monad \(F\) is Frobenius provided we have \(F=G\) and then \(\mathbb{A}_F\simeq \mathbb{A}^F\). Here we investigate which kind of isomorphisms can be obtained for non-unital monads and non-counital comonads. For this we observe that the mentioned isomorphism  is in fact an isomorphisms between \(\mathbb{A}_F\) and the category of bimodules \(\mathbb{A}^F_F\) subject to certain compatibility conditions (Frobenius bimodules). Eventually we obtain that for a weak monad \((F,m,\eta)\) and a weak comonad  \((F,\delta,\varepsilon)\)  satisfying \(Fm\cdot \delta F = \delta \cdot m = mF\cdot F\delta\) and \(m\cdot F\eta = F\varepsilon\cdot \delta\), the category of compatible \(F\)-modules is isomorphic to the category of compatible Frobenius bimodules and the category of compatible \(F\)-comodules.
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spelling admjournalluguniveduua-article-1332016-07-12T10:09:40Z Weak Frobenius monads and Frobenius bimodules Wisbauer, Robert pairing of functors; adjoint functors; weak (co)monads; Frobenius monads; firm modules; cofirm comodules; separability 18A40, 18C20, 16T1 As observed by  Eilenberg and  Moore (1965), for a monad \(F\) with right adjoint comonad \(G\) on any category \(\mathbb{A}\),  the category of unital \(F\)-modules \(\mathbb{A}_F\) is isomorphic to the category of counital \(G\)-comodules \(\mathbb{A}^G\). The monad \(F\) is Frobenius provided we have \(F=G\) and then \(\mathbb{A}_F\simeq \mathbb{A}^F\). Here we investigate which kind of isomorphisms can be obtained for non-unital monads and non-counital comonads. For this we observe that the mentioned isomorphism  is in fact an isomorphisms between \(\mathbb{A}_F\) and the category of bimodules \(\mathbb{A}^F_F\) subject to certain compatibility conditions (Frobenius bimodules). Eventually we obtain that for a weak monad \((F,m,\eta)\) and a weak comonad  \((F,\delta,\varepsilon)\)  satisfying \(Fm\cdot \delta F = \delta \cdot m = mF\cdot F\delta\) and \(m\cdot F\eta = F\varepsilon\cdot \delta\), the category of compatible \(F\)-modules is isomorphic to the category of compatible Frobenius bimodules and the category of compatible \(F\)-comodules. Lugansk National Taras Shevchenko University 2016-07-12 Article Article Peer-reviewed Article application/pdf https://admjournal.luguniv.edu.ua/index.php/adm/article/view/133 Algebra and Discrete Mathematics; Vol 21, No 2 (2016) 2415-721X 1726-3255 en https://admjournal.luguniv.edu.ua/index.php/adm/article/view/133/pdf Copyright (c) 2016 Algebra and Discrete Mathematics
spellingShingle pairing of functors
adjoint functors
weak (co)monads
Frobenius monads
firm modules
cofirm comodules
separability
18A40
18C20
16T1
Wisbauer, Robert
Weak Frobenius monads and Frobenius bimodules
title Weak Frobenius monads and Frobenius bimodules
title_full Weak Frobenius monads and Frobenius bimodules
title_fullStr Weak Frobenius monads and Frobenius bimodules
title_full_unstemmed Weak Frobenius monads and Frobenius bimodules
title_short Weak Frobenius monads and Frobenius bimodules
title_sort weak frobenius monads and frobenius bimodules
topic pairing of functors
adjoint functors
weak (co)monads
Frobenius monads
firm modules
cofirm comodules
separability
18A40
18C20
16T1
topic_facet pairing of functors
adjoint functors
weak (co)monads
Frobenius monads
firm modules
cofirm comodules
separability
18A40
18C20
16T1
url https://admjournal.luguniv.edu.ua/index.php/adm/article/view/133
work_keys_str_mv AT wisbauerrobert weakfrobeniusmonadsandfrobeniusbimodules