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Related papers: Classifying exact categories via Wakamatsu tilting

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We construct the reduction of an exact category with a twist functor with respect to an element of its graded center in presence of an exact-conservative forgetful functor annihilating this central element. The procedure allows, e.g., to…

K-Theory and Homology · Mathematics 2018-11-13 Leonid Positselski

We prove that over an algebraically closed field there is a representation embedding from the category of classical Kronecker-modules without the simple injective into the category of finite-dimensional modules over any…

Representation Theory · Mathematics 2023-05-30 Klaus Bongartz

Let $\hat{R}$ be the $I$-adic completion of a commutative ring $R$ with respect to a finitely generated ideal $I$. We give a necessary and sufficient criterion for the category of perfect complexes over $\hat{R}$ to be equivalent to the…

Commutative Algebra · Mathematics 2024-11-25 Paul Balmer , Beren Sanders

A full subcategory of modules over a commutative ring $R$ is wide if it is abelian and closed under extensions. Hovey \cite{wide} gave a classification of wide subcategories of finitely presented modules over regular coherent rings in terms…

K-Theory and Homology · Mathematics 2009-12-03 Sunil K. Chebolu

We apply tilting theory over preprojective algebras $Lambda$ to a study of moduli space of $Lambda$-modules. We define the categories of semistable modules and give an equivalence, so-called reflection functors, between them by using…

Algebraic Geometry · Mathematics 2011-01-19 Yuhi Sekiya , Kota Yamaura

We develop abstract nonsense for module categories over monoidal categories (this is a straightforward categorification of modules over rings). As applications we show that any semisimple monoidal category with finitely many simple objects…

Quantum Algebra · Mathematics 2007-05-23 Viktor Ostrik

Let $\mathcal{A}$ be an abelian length category containing a $d$-cluster tilting subcategory $\mathcal{M}$. We prove that a subcategory of $\mathcal{M}$ is a $d$-torsion class if and only if it is closed under $d$-extensions and…

Representation Theory · Mathematics 2025-02-12 Jenny August , Johanne Haugland , Karin M. Jacobsen , Sondre Kvamme , Yann Palu , Hipolito Treffinger

We study ideal cotorsion pairs associated to weak proper classes of triangles in extension closed subcategories of triangulated categories. This approach allows us to extend the recent ideal approximations theory developed by Fu, Herzog et…

Category Theory · Mathematics 2017-07-04 Simion Breaz , George-Ciprian Modoi

We introduce the notion of an $n$-exact dg-category. This notion provides a higher analogue of Chen's exact dg-category, in the sense that the case where $n$ equals 1 recovers exact dg-categories. We prove that, under a suitable vanishing…

Category Theory · Mathematics 2026-04-08 Nao Mochizuki , Hiroyuki Nakaoka

Let $R$ be a commutative ring. A full additive subcategory $\C$ of $R$-modules is triangulated if whenever two terms of a short exact sequence belong to $\C$, then so does the third term. In this note we give a classification of…

Commutative Algebra · Mathematics 2009-12-03 Sunil K. Chebolu

We shall show that the stable categories of graded Cohen-Macaulay modules over quotient singularities have tilting objects. In particular, these categories are triangle equivalent to derived categories of finite dimensional algebras. Our…

Representation Theory · Mathematics 2011-02-17 Osamu Iyama , Ryo Takahashi

Enomoto showed for finite dimensional algebras that the classification of exact structures on the category of finitely generated projective modules can be reduced to the classification of 2-regular simple modules. In this article, we give a…

Combinatorics · Mathematics 2020-07-15 Rene Marczinzik , Martin Rubey , Christian Stump

Tilting objects play a key role in the study of triangulated categories. A famous result due to Iyama and Takahashi asserts that the stable categories of graded maximal Cohen-Macaulay modules over quotient singularities have tilting…

Rings and Algebras · Mathematics 2016-01-28 Izuru Mori , Kenta Ueyama

We give a complete list of indecomposable exact module categories over the finite tensor category $\mathrm{Rep}(u_q(\mathfrak{sl}_2))$ of representations of the small quantum group $u_q(\mathfrak{sl}_2)$, where $q$ is a root of unity of odd…

Quantum Algebra · Mathematics 2025-03-28 Daisuke Nakamura , Taiki Shibata , Kenichi Shimizu

We give an elementary construction of the exact completion of a weakly lex category for categories enriched in the cartesian closed category $\mathsf{Pos}$ of partially ordered sets. Paralleling the ordinary case, we characterize categories…

Category Theory · Mathematics 2025-12-16 Vasileios Aravantinos-Sotiropoulos

For a finite-dimensional gentle algebra, it is already known that the functorially finite torsion classes of its category of finite-dimensional modules can be classified using a combinatorial interpretation, called maximal non-crossing sets…

Representation Theory · Mathematics 2020-09-23 Aaron Chan , Laurent Demonet

We consider a notion of exact sequences in any -not necessarily exact- pointed category relative to a given (E;M)-factorization structure. We apply this notion to introduce and investigate a new notion of exact sequences of semimodules over…

Category Theory · Mathematics 2011-11-03 Jawad Abuhlail

We study the class of modules, called cosilting modules, which are defined as the categorical duals of silting module. Several characterizations of these modules and connections with silting modules are presented. We prove that Bazzoni…

Rings and Algebras · Mathematics 2017-03-01 Simion Breaz , Flaviu Pop

In this paper, we study the ideal approximation theory associated to almost $n$-exact structures in the $n$-exangulated category. The notions of $n$-ideal cotorsion pairs and $n$-$\mathbb{F}$-phantom morphisms are introduced and studied. In…

Category Theory · Mathematics 2022-07-28 Yucheng Wang , Jiaqun Wei

Let Q be a finite quiver without oriented cycles, and let k be an algebraically closed field. The main result in this paper is that there is a natural bijection between the elements in the associated Coxeter group W_Q and the cofinite…

Representation Theory · Mathematics 2019-02-20 Steffen Oppermann , Idun Reiten , Hugh Thomas
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