English
Related papers

Related papers: Pre-$(n+2)$-angulated categories

200 papers

This note proposes a new method to complete a triangulated category, which is based on the notion of a Cauchy sequence. We apply this to categories of perfect complexes. It is shown that the bounded derived category of finitely presented…

Representation Theory · Mathematics 2019-10-31 Tobias Barthel , Bernhard Keller , Henning Krause

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 $\mathscr{C}$ be an $n$-exangulated category. In this note, we show that if $\mathscr{C}$ is locally finite, then $\mathscr{C}$ has Auslander-Reiten $n$-exangles. This unifies and extends results of Xiao-Zhu, Zhu-Zhuang, Zhou and…

Representation Theory · Mathematics 2023-02-07 Jian He , Jiangsheng Hu , Dongdong Zhang , Panyue Zhou

Let $(\mathscr{C},\mathbb{E},\mathfrak{s})$ be an $n$-exangulated category with enough projectives and enough injectives, and $\mathscr{X}$ be a cluster-tilting subcategory of $\mathscr{C}$. Liu and Zhou have shown that the quotient…

Representation Theory · Mathematics 2024-10-04 Jian He , Hangyu Yin , Panyue Zhou

Let C be a triangulated category with a Serre functor S and X a non-zero contravariantly finite rigid subcategory of C. Then X is cluster tilting if and only if the quotient category C/X is abelian and S(X)=X[2]. As an application, this…

Representation Theory · Mathematics 2020-03-27 Panyue Zhou

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

We introduce the notion of a rank function on a $(d+2)$-angulated category $\mathcal{C}$ which generalises the notion of a rank function on a triangulated category. Inspired by work of Chuang and Lazarev, for $d$ an odd positive integer, we…

Representation Theory · Mathematics 2025-08-07 David Nkansah

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

Let $R$ be an artin ring and $\Theta=\{\Theta(1),\Theta(2),\cdots,\Theta(n)\}$ be a family of objects in an artin extriangulated $R$-category $(\cal C,\mathbb{E},\mathfrak{s})$ such that $\mathbb{E}(\Theta(j),\Theta(i))=0$ for all $j\geq…

Representation Theory · Mathematics 2021-08-25 Panyue Zhou

This is the fourth (and last) prepublication version of a book on derived categories, that will be published by Cambridge University Press. The purpose of the book is to provide solid foundations for the theory of derived categories, and to…

Category Theory · Mathematics 2020-01-07 Amnon Yekutieli

In the category of finitely generated modules over an artinian ring, we classify all the abelian exact subcategories closed under predecessors or, equivalently, all the split torsion pairs with torsion-free class closed under quotients.

Rings and Algebras · Mathematics 2007-05-23 Ibrahim Assem , Manuel Saorin

Higher homological algebra was introduced by Iyama. It is also known as $n$-homological algebra where $n \geq 2$ is a fixed integer, and it deals with $n$-cluster tilting subcategories of abelian categories. All short exact sequences in…

Representation Theory · Mathematics 2015-08-13 Peter Jorgensen

Let $n$ be a positive integer. We show that an $n$-extension closed subcategory of an $n$-exangulated category naturally inherits an $n$-exangulated structure through restriction of the ambient $n$-exangulated structure. Furthermore, we…

Representation Theory · Mathematics 2026-05-14 Carlo Klapproth

Let $\mathcal C$ be a $(d+2)$-angulated category. In this paper, we define the notions of cotorsion pairs and weak cotorsion pairs in $\mathcal C$, which are generalizations of the classical cotorsion pairs in triangulated categories. As an…

Representation Theory · Mathematics 2024-11-28 Huimin Chang , Panyue Zhou

The goal of this note is to spell out the (apparently well-known and intuitively clear) notion of abelian category over an algebraic stack. In the future we will discuss the (much less evident) notion, when instead of an abelian category…

Algebraic Geometry · Mathematics 2007-05-23 Dennis Gaitsgory

Given an additive category $\mathcal{C}$ and an integer $n\geqslant 2$. We form a new additive category $\mathcal{C}[\epsilon]^n$ consisting of objects $X$ in $\mathcal{C}$ equipped with an endomorphism $\epsilon_X$ satisfying…

Representation Theory · Mathematics 2019-12-24 Xi Tang , Zhaoyong Huang

We introduce a relative tilting theory in abelian categories and show that this work offers a unified framework of different previous notions of tilting, ranging from Auslander-Solberg relative tilting modules on Artin algebras to…

Representation Theory · Mathematics 2023-11-27 Alejandro Argudin Monroy , Octavio Mendoza Hernandez

A notion of balanced pairs in an extriangulated category with a negative first extension is defined in this article. We prove that there exists a bijective correspondence between balanced pairs and proper classes $\xi$ with enough…

Representation Theory · Mathematics 2021-09-06 Jian He , Panyue Zhou

We characterize virtual double categories of enriched categories, functors, and profunctors by introducing a new notion of double-categorical colimits. Our characterization is strict in the sense that it is up to equivalence between virtual…

Category Theory · Mathematics 2026-04-07 Yuto Kawase

We define the notion of 2-filtered 2-category and give an explicit construction of the bicolimit of a category valued 2-functor. A category considered as a trivial 2-category is 2-filtered if and only if it is a filtered category, and our…

Category Theory · Mathematics 2021-03-17 Eduardo J. Dubuc , Ross Street