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Related papers: Quasi-cotilting modules and torsion-free classes

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Prime objects were defined as generalization of simple objects in the categories of rings (modules). In this paper we introduce and investigate what turns out to be a suitable generalization of simple corings (simple comodules), namely…

Rings and Algebras · Mathematics 2007-05-23 Jawad A. Abuhlail

We study the category of Sp-equivariant modules over the infinite variable polynomial ring, where Sp denotes the infinite symplectic group. We establish a number of results about this category: for instance, we show that every finitely…

Commutative Algebra · Mathematics 2022-03-15 Steven V Sam , Andrew Snowden

For a semi-separated noetherian scheme, we show that the category of cotorsion Gorenstein flat quasi-coherent sheaves is Frobenius and a natural non-affine analogue of the category of Gorenstein projective modules over a noetherian ring. We…

Commutative Algebra · Mathematics 2020-07-16 Lars Winther Christensen , Sergio Estrada , Peder Thompson

We define a quasimodule Q over a bounded lattice L in an analogous way as a module over a semiring is defined. The essential difference is that L need not be distributive. Also for quasimodules there can be introduced the concepts of inner…

Rings and Algebras · Mathematics 2024-11-04 Ivan Chajda , Helmut Länger

One proves that each almost local-global semihereditary ring has the stacked basis property and is almost Bezout. If M is a finitely presented module, its torsion part tM is a direct sum of cyclic modules where the family of annhilators is…

Rings and Algebras · Mathematics 2007-10-03 Francois Couchot

It is proved that every commutative ring whose RD-injective modules are $\Sigma$-RD-injective is the product of a pure semi-simple ring and a finite ring. A complete characterization of commutative rings for which each artinian…

Rings and Algebras · Mathematics 2014-02-18 Francois Couchot

In this paper, we introduce and study e-injective semimodules, in particular over additively idempotent semirings. We completely characterize semirings all of whose semimodules are e-injective, describe semirings all of whose projective…

Rings and Algebras · Mathematics 2016-08-10 J. Y. Abuhlail , S. N. Il'in , Y. Katsov , T. G. Nam

This paper is an MGM version of arXiv.org:1703.04266 and arXiv:1907.03364, and a follow-up to Section 5 of arXiv:1503.05523. In the setting of a commutative ring $S$ with a weakly proregular finitely generated ideal $J\subset S$, we…

Commutative Algebra · Mathematics 2025-12-08 Leonid Positselski

We prove that an abelian category equipped with an ample sequence of objects is equivalent to the quotient of the category of coherent modules over the corresponding algebra by the subcategory of finite-dimensional modules. In the…

Rings and Algebras · Mathematics 2007-05-23 Alexander Polishchuk

We introduce a notion of quasi-lisse vertex algebras, which generalizes admissible affine vertex algebras. We show that the normalized character of an ordinary module over a quasi-lisse vertex operator algebra has a modular invariance…

Quantum Algebra · Mathematics 2017-07-24 Tomoyuki Arakawa , Kazuya Kawasetsu

Let $R\to A$ be a homomorphism of associative rings, and let $(\mathcal F,\mathcal C)$ be a hereditary complete cotorsion pair in $R\mathsf{-Mod}$. Let $(\mathcal F_A,\mathcal C_A)$ be the cotorsion pair in $A\mathsf{-Mod}$ in which…

Rings and Algebras · Mathematics 2023-04-19 Leonid Positselski

Let $(\mathcal{G},\otimes)$ be any closed symmetric monoidal Grothendieck category. We show that K-flat covers exist universally in the category of chain complexes and that the Verdier quotient of $K(\mathcal{G})$ by the K-flat complexes is…

Algebraic Geometry · Mathematics 2023-06-09 Sergio Estrada , James Gillespie , Sinem Odabaşı

Let $R$ be a commutative ring with identity and $M$ be a unitary $R$-module. The aim of this paper is to extend the notion of quasi $J$-ideals of commutative rings to quasi $J$-submodules of modules. We call a proper submodule $N$ of $M$ a…

Commutative Algebra · Mathematics 2021-02-23 Ece Yetkin Celikel , Hani A. Khashan

We construct the semi-infinite tensor structure on the semiderived category of quasi-coherent torsion sheaves on an ind-scheme endowed with a flat affine morphism into an ind-Noetherian ind-scheme with a dualizing complex. The semitensor…

Algebraic Geometry · Mathematics 2023-09-21 Leonid Positselski

We are interested in characterising the commutative rings for which a $1$-tilting cotorsion pair $(\mathcal{A}, \mathcal{T})$ provides for covers, that is when the class $\mathcal{A}$ is a covering class. We use Hrbek's bijective…

Commutative Algebra · Mathematics 2020-06-03 Silvana Bazzoni , Giovanna Le Gros

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

We define a type B analogue of the category of finite sets with surjections, and we study the representation theory of this category. We show that the opposite category is quasi-Grobner, which implies that submodules of finitely generated…

Representation Theory · Mathematics 2020-11-04 Nicholas Proudfoot

We introduce the notion of torsion-simple objects in an abelian category: these are the objects which are always either torsion or torsion-free with respect to any torsion pair. We present some general results concerning their properties,…

Representation Theory · Mathematics 2023-12-08 Sergio Pavon

Let k be a field and TV the tensor algebra on a k-vector space V of dimension n>1. This paper proves that the quotient category QGr(TV) := Gr(TV)/Fdim of graded TV-modules modulo those that are unions of finite dimensional modules is…

Rings and Algebras · Mathematics 2011-07-19 S. Paul Smith

We consider an arbitrary Abelian category $\mathcal{A}$ and a subcategory $\mathcal{T}$ closed under extensions and direct summands, and characterize those $\mathcal{T}$ that are (semi-)special preenveloping in $\mathcal{A}$; as a…

Representation Theory · Mathematics 2021-12-28 Carlos E. Parra , Manuel Saorín , Simone Virili