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Related papers: A note on torsion modules with pure embeddings

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We prove that all quasi-cotilting modules are pure-injective and cofinendo. It follows that the class CogenM is always a covering class whenever M is a quasi-cotilting module. Some characterizations of quasi-cotilting modules are given. As…

Rings and Algebras · Mathematics 2016-01-08 Peiyu Zhang , Jiaqun Wei

In this paper, we characterize quasi-integrable modules, of nonzero level, over twisted affine Lie superalgebras. We show that quasi-integrable modules are not necessarily highest weight modules. We prove that each quasi-integrable module…

Representation Theory · Mathematics 2022-02-02 Malihe Yousofzadeh

Weakly stable torsion classes were introduced by the author and Yekutieli to provide a torsion theoretic characterisation of the notion of weak proregularity from commutative algebra. In this paper we investigate weakly stable torsion…

Rings and Algebras · Mathematics 2018-08-09 Rishi Vyas

The formalism of injective stabilization of additive functors is used to define a new notion of the torsion submodule of a module. It applies to arbitrary modules over arbitrary rings. For arbitrary modules over commutative domains it…

Representation Theory · Mathematics 2019-12-03 Alex Martsinkovsky , Jeremy Russell

It is conjectured that for fixed $A$, $r \ge 1$, and $d \ge 1$, there is a uniform bound on the size of the torsion submodule of a Drinfeld $A$-module of rank $r$ over a degree $d$ extension $L$ of the fraction field $K$ of $A$. We verify…

Number Theory · Mathematics 2016-09-06 Bjorn Poonen

Tight and essentially tight modules generalize weakly injective modules. Essential tightness requires embeddings to be essential. This restriction makes the two notions totally different. In this note, we investigate cases when those two…

Rings and Algebras · Mathematics 2025-12-09 Nasief Khlaif , Mohammad Saleh

We consider embeddings in a torsion-free hyperbolic group which are elementary in the sense of first-order logic. We give a description of these embeddings in terms of Sela's hyperbolic towers. We deduce as a corollary that subgroups…

Group Theory · Mathematics 2012-06-18 Chloé Perin

Recently, in a series of papers "simple" versions of direct-injective and direct-projective modules have been investigated. These modules are termed as "simple-direct-injective" and "simple-direct-projective", respectively. In this paper,…

Rings and Algebras · Mathematics 2020-04-13 Engin Büyükaşık , Özlem Demir , Müge Diril

We classify the simple quantum group modules with finite dimensional weight spaces when the quantum parameter $q$ is transcendental and the Lie algebra is not of type $G_2$. This is part $2$ of the story. The first part being Irreducible…

Representation Theory · Mathematics 2015-07-24 Dennis Hasselstrøm Pedersen

We denote by $\mathcal{W}$ the class of all pure projective modules. Present article we investigate $\mathcal{W}$-injective modules and these modules are defined via the vanishing of cohomology of pure projective modules. First we prove…

Tensor products usually have nonzero torsion. This is a central theme of Auslander's paper "Modules over unramified regular local rings"; the theme continues in the work of Huneke and Wiegand. The main focus in this note is on tensor powers…

Commutative Algebra · Mathematics 2014-12-22 Olgur Celikbas , Srikanth B. Iyengar , Greg Piepmeyer , Roger Wiegand

In this paper we determine the torsion free rank of the group of endotrivial modules for any finite group of Lie type, in both defining and non-defining characteristic. On our way to proving this, we classify the maximal rank $2$ elementary…

Group Theory · Mathematics 2022-07-20 Jon F. Carlson , Jesper Grodal , Nadia Mazza , Daniel K. Nakano

Let A be a commutative ring, and let \a = \frak{a} be a finitely generated ideal in it. It is known that a necessary and sufficient condition for the derived \a-torsion and \a-adic completion functors to be nicely behaved is the weak…

Rings and Algebras · Mathematics 2018-08-08 Rishi Vyas , Amnon Yekutieli

Let $\Lambda$ be a finite-dimensional associative algebra. The torsion classes of $mod\, \Lambda$ form a lattice under containment, denoted by $tors\, \Lambda$. In this paper, we characterize the cover relations in $tors\, \Lambda$ by…

Representation Theory · Mathematics 2017-10-25 Emily Barnard , Andrew T. Carroll , Shijie Zhu

If in a given rank $r$, there is an irreducible complex local system with torsion determinant and quasi-unipotent monodromies at infinity on a smooth quasi-projective variety, then for every prime number $\ell$, there is an absolutely…

Algebraic Geometry · Mathematics 2023-02-22 Johan de Jong , Hélène Esnault

Let (R,m) be a noetherian local ring and let $\mathcal{C}$ be the class of all R-modules M which possess a reflexive submodule U such that M/U is finitely generated. For every R-module $M\in \mathcal{C}$ the canonical embedding $\varphi:…

Commutative Algebra · Mathematics 2014-03-25 Helmut Zöschinger

The Bershadsky--Polyakov algebras are the subregular quantum hamiltonian reductions of the affine vertex operator algebras associated with $\mathfrak{sl}_3$. In arXiv:2007.00396 [math.QA], we realised these algebras in terms of the regular…

Quantum Algebra · Mathematics 2023-12-01 Drazen Adamovic , Kazuya Kawasetsu , David Ridout

The aim of this paper is to describe the classes of strongly flat and weakly cotorsion modules with respect to a multiplicative subset or a finite collection of multiplicative subsets in a commutative ring. The strongly flat modules are…

Commutative Algebra · Mathematics 2019-04-08 Leonid Positselski , Alexander Slavik

In this work we introduce a new concept, namely, $\tau_{s}$-extending modules (rings) which is torsion-theoretic analogues of extending modules and then we extend many results from extending modules to this new concept. For instance we show…

Rings and Algebras · Mathematics 2022-01-03 Semra Dogruoz , Azime Tarhan

Suppose that $(\mathcal{F},\mathcal{M})$ is an injective structure of $R$-Mod such that the class $\mathcal{F}$ is closed for direct limits, then two modules in $\mathcal{M}$ are isomorphic if there are maps in $\mathcal{F}$ from each one…

Rings and Algebras · Mathematics 2024-07-30 Mohanad Farhan Hamid