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Related papers: Ideal approximation in $n$-angulated categories

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Extriangulated categories were introduced by Nakaoka and Palu by extracting the similarities between exact categories and triangulated categories. In this article, we introduce and study the notion of $\xi$-tilting object in an…

Representation Theory · Mathematics 2020-12-17 Yuxia Mei , Jiaqun Wei

We systematically develop the theory of definable functors between compactly generated triangulated categories. Such functors preserve pure triangles, pure injective objects, and definable subcategories, and as such appear in a wide range…

Category Theory · Mathematics 2025-03-03 Isaac Bird , Jordan Williamson

These notes for a master class at Aarhus University (March 22--24, 2023) provide an introduction to the theory of completion for triangulated categories.

Category Theory · Mathematics 2023-09-06 Henning Krause

We introduce a new concept of s-recollements of extriangulated categories, which generalizes recollements of abelian categories, recollements of triangulated categories, as well as recollements of extriangulated categories. Moreover, some…

Representation Theory · Mathematics 2021-07-30 Yonggang Hu , Panyue Zhou

These notes are meant to provide a rapid introduction to triangulated categories. We start with the definition of an additive category and end with a glimps of tilting theory. Some exercises are included.

K-Theory and Homology · Mathematics 2007-05-23 Behrang Noohi

We classify certain subcategories in quotients of exact categories. In particular, we classify the triangulated and thick subcategories of an algebraic triangulated category, i.e. the stable category of a Frobenius category.

Category Theory · Mathematics 2017-12-15 Emilie Arentz-Hansen

We study cocoverings of triangulated categories, in the sense of Rouquier, and prove that for any regular cardinal $\alpha$ the condition of $\alpha$-compactness, in the sense of Neeman, is local with respect to such cocoverings. This was…

Category Theory · Mathematics 2009-04-20 Daniel Murfet

In the context of ideally exact categories, we introduce the notions of internal coherent action and internal ideal action that generalise different aspects of unital actions of rings and algebras. We prove that every ideal action is…

Category Theory · Mathematics 2026-05-25 Manuel Mancini , Giuseppe Metere , Federica Piazza

Our work is a fundamental study of the notion of approximation in V-categories and in (U,V)-categories, for a quantale V and the ultrafilter monad U. We introduce auxiliary, approximating and Scott-continuous distributors, the way-below…

Category Theory · Mathematics 2010-04-14 Dirk Hofmann , Pawel Waszkiewicz

We define admissible and weakly admissible subcategories in exact categories and prove that the former induce semi-orthogonal decompositions on the derived categories. We develop the theory of thin exact categories, an exact-category…

Representation Theory · Mathematics 2024-06-25 Agnieszka Bodzenta , Alexey Bondal

The main result of this paper is that there is an additive equivalence between $\overline{\mathcal{C}}_n$, the Paquette-Yildirim completion of the discrete cluster categories of Dynkin type $A_{\infty}$, and the perfect derived category of…

Representation Theory · Mathematics 2025-10-15 Marina Godinho , Dave Murphy

A new proof of the classification for tensor ideal thick subcategories of the bounded derived category, and the stable category, of modular representations of a finite group is obtained. The arguments apply more generally to yield a…

Representation Theory · Mathematics 2012-02-01 Jon F. Carlson , Srikanth B. Iyengar

Herschend-Liu-Nakaoka introduced the notion of $n$-exangulated categories. It is not only a higher dimensional analogue of extriangulated categories defined by Nakaoka-Palu, but also gives a simultaneous generalization of $n$-exact…

Representation Theory · Mathematics 2021-08-25 Yu Liu , Panyue Zhou

We show that the category of orbits of the bounded derived category of a hereditary category under a well-behaved autoequivalence is canonically triangulated. This answers a question by A. Buan, R. Marsh and I. Reiten which appeared in…

Representation Theory · Mathematics 2007-05-23 Bernhard Keller

We give a general parametrization of all the recollement data for a triangulated category with a set of generators. From this we deduce a characterization of when a perfectly generated (or aisled) triangulated category is a recollement of…

Representation Theory · Mathematics 2010-10-05 Pedro Nicolas , Manuel Saorin

We show certain standard constructions of the theory of Verdier triangulated categories to be valid in the Heller triangulated framework as well; viz. Karoubi hull, exactness of adjoints, localisation.

K-Theory and Homology · Mathematics 2013-01-15 Matthias Kuenzer

We modify the axioms of triangulated categories to include both higher triangles and distinguished maps of higher triangles. The distinguished maps are specializations of Neeman's ``good'' maps of $2$-triangles. The axioms both simplify…

Category Theory · Mathematics 2023-12-13 Husniyah Alzubaidi , Antony Maciocia

We show that the idempotent completion of an n-angulated category admits a unique n-angulated structure such that the inclusion is an n-angulated functor, which satisfies a universal property.

Category Theory · Mathematics 2017-01-17 Zengqiang Lin

We introduce and study relatively divisible and relatively flat objects in exact categories in the sense of Quillen. For every relative cotorsion pair $(\mathcal{A},\mathcal{B})$ in an exact category $\mathcal{C}$, $\mathcal{A}$ coincides…

Category Theory · Mathematics 2018-10-30 Septimiu Crivei , Derya Keskin Tütüncü

In a general triangulated category, the finiteness of the finitistic dimension serves as a prerequisite for a categorical obstruction, via the singularity category, to the existence of bounded $t$-structures. In this paper, we investigate…

Representation Theory · Mathematics 2026-04-14 Hongxing Chen , Xiaohu Chen , Jinbi Zhang