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Related papers: Cotorsion pairs in comma categories

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In this paper, we first give a characterization of silting objects in the comma category Assume that C1 and C2 are two subcategories of left R-modules, D1 and D2 be two subcategories of left S-modules. We mainly prove that (C1, C2) and (D1,…

Rings and Algebras · Mathematics 2024-05-28 Peiyu Zhang , Xinyu Wang , Dajun Liu , Li Wang , Jiaqun Wei

In the previous article "Hearts of twin cotorsion pairs on exact categories", we introduced the notion of the heart for any cotorsion pair on an exact category with enough projectives and injectives, and showed that it is an abelian…

Representation Theory · Mathematics 2020-03-16 Yu Liu

We study the category $\mathrm{Rep}(Q,\mathcal{M})$ of representations of a quiver $Q$ with values in an abelian category $\mathcal{M}$. Under certain assumptions, we show that every cotorsion pair $(\mathcal{A},\mathcal{B})$ in…

Category Theory · Mathematics 2019-09-18 Henrik Holm , Peter Jorgensen

For a commutative noetherian ring $R$, we classify all the hereditary cotorsion pairs cogenerated by pure-injective modules of finite injective dimension. The classification is done in terms of integer-valued functions on the spectrum of…

Commutative Algebra · Mathematics 2024-11-08 Dolors Herbera , Michal Hrbek , Giovanna Le Gros

Let $( \mathcal{A^{'}},\mathcal{A},\mathcal{A^{''}},i^\ast,i_\ast,i^!,j_!,j^\ast,j_\ast)$ be a recollement of abelian categories. Suppose that we are given two cotorsion pairs $({\mathcal{U^{'}}},\mathcal{V{'}})$ and…

Representation Theory · Mathematics 2026-03-10 Jinrui Yang , Yongyun Qin

We show that a complete hereditary cotorsion pair $(\C,\C^\bot)$ in an exact category $\E$, together with a subcategory $\Z\subseteq\E$ containing $\C^\bot$, determines a Waldhausen category structure on the exact category $\C$, in which…

K-Theory and Homology · Mathematics 2020-06-16 Maru Sarazola

We give a simultaneous generalization of recollements of abelian categories and triangulated categories, which we call recollements of extriangulated categories. For a recollement $(\mathcal{A}$, $\mathcal{B}$, $\mathcal{C})$ of…

Representation Theory · Mathematics 2020-12-08 Li Wang , Jiaqun Wei , Haicheng Zhang

We give a simultaneous generalization of exact categories and triangulated categories, which is suitable for considering cotorsion pairs, and which we call extriangulated categories. Extension-closed, full subcategories of triangulated…

Category Theory · Mathematics 2019-04-29 Hiroyuki Nakaoka , Yann Palu

Let $\mathcal{A}$ be an abelian category, or more generally a weakly idempotent complete exact category, and suppose we have two complete hereditary cotorsion pairs $(\mathcal{Q}, \widetilde{\mathcal{R}})$ and $(\widetilde{\mathcal{Q}},…

Algebraic Topology · Mathematics 2014-06-11 James Gillespie

Hearts of cotorsion pairs on extriangulated categories are abelian categories. On the other hand, hearts of twin cotorsion pairs are not always abelian. They were shown to be semi-abelian by Liu and Nakaoka. Moreover, Hassoun and Shah…

Representation Theory · Mathematics 2025-06-25 Yu Liu , Wuzhong Yang , Panyue Zhou

Let $(\mathcal{T}',\mathcal{T},\mathcal{T}'')$ be a recollement of triangulated categories.A complete ideal cotorsion pair in $\mathcal{T}$ induces complete ideal cotorsion pairs in $\mathcal{T}'$ and $\mathcal{T}''$. In addition, if…

Category Theory · Mathematics 2026-02-20 Qikai Wang , Haiyan Zhu

Let $(\mathcal{A}, \mathcal{B}, \mathcal{C})$ be a recollement of extriangulated categories.In this paper, we first show how to obtain an $n$-cotorsion pair in $\mathcal{B}$ from given $n$-cotorsion pairs in $\mathcal{A}$ and $\mathcal{C}$.…

Representation Theory · Mathematics 2025-08-29 Xin Ma , Panyue Zhou

In this article, we study the heart of a cotorsion pairs on an exact category and a triangulated category in a unified meathod, by means of the notion of an extriangulated category. We prove that the heart is abelian, and construct a…

Category Theory · Mathematics 2020-03-16 Yu Liu , Hiroyuki Nakaoka

Given two (hereditary) complete cotorsion pairs $(\mathcal{X}_1,\mathcal{Y}_1)$ and $(\mathcal{X}_2,\mathcal{Y}_2)$ in an exact category with $\mathcal{X}_1\subseteq \mathcal{Y}_2$, we prove that $\left({\rm Smd}\langle…

K-Theory and Homology · Mathematics 2026-02-20 Qikai Wang , Haiyan Zhu

We study the category $\operatorname{Rep}(Q,\mathcal{C})$ of representations of a quiver $Q$ with values in an abelian category $\mathcal{C}$. For this purpose we introduce the mesh and the cone-shape cardinal numbers associated to the…

Representation Theory · Mathematics 2023-11-22 Alejandro Argudín Monroy , Octavio Mendoza

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

Let $F:\mathcal{A}\to \mathcal{B}$ be a left adjoint between abelian categories and let $Ch(F)$ be the induced left adjoint on chain complexes. If the abelian categories $\mathcal{A}$ and $\mathcal{B}$ are equipped with sufficiently nice…

Category Theory · Mathematics 2021-05-25 Rene Recktenwald

To a big n-tilting object in a complete, cocomplete abelian category A with an injective cogenerator we assign a big n-cotilting object in a complete, cocomplete abelian category B with a projective generator, and vice versa. Then we…

Category Theory · Mathematics 2021-01-13 Leonid Positselski , Jan Stovicek

Hovey's correspondence between model structures and cotorsion pairs in the setting of abelian categories, has been generalized by Nakaoka-Palu, using two cotorsion pairs, to the setting of weakly idempotent complete extriangulated…

Representation Theory · Mathematics 2026-03-10 Jiangsheng Hu , Dongdong Zhang , Pu Zhang , Panyue Zhou

In this paper we introduce a special kind of relative (co)resolutions associated to a pair of classes of objects in an abelian category $\mathcal{C}.$ We will see that, by studying these relative (co)resolutions, we get a possible…

Representation Theory · Mathematics 2024-06-11 Alejandro Argudín Monroy , Octavio Mendoza Hernández