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

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By using the approach in \cite{XX2006} to Hall algebras arising in homologically finite triangulated categories, we find an `almost' associative multiplication structure for indecomposable objects in a 2-periodic triangulated category. As…

Representation Theory · Mathematics 2010-01-25 Fan Xu

The purpose of this paper is to initiate a development of a new non-pointed counterpart of semi-abelian categorical algebra. We are making, however, only the first step in it by giving equivalent definitions of what we call ideally exact…

Category Theory · Mathematics 2023-08-21 George Janelidze

Herschend-Liu-Nakaoka introduced the notion of $n$-exangulated categories as higher dimensional analogues of extriangulated categories defined by Nakaoka-Palu. The class of $n$-exangulated categories contains $n$-exact categories and…

Representation Theory · Mathematics 2020-05-15 Yu Liu , Panyue Zhou

We propose a new framework for the study of homological properties for (compactly generated) triangulated categories such as regularity, finiteness of global or finitistic dimension, gorensteinness or injective generation and the relation…

Representation Theory · Mathematics 2025-12-23 Panagiotis Kostas , Chrysostomos Psaroudakis , Jorge Vitória

Internal categories feature notions of limit and completeness, as originally proposed in the context of the effective topos. This paper sets out the theory of internal completeness in a general context, spelling out the details of the…

Category Theory · Mathematics 2020-04-21 Enrico Ghiorzi

We define novel fully combinatorial models of higher categories. Our definitions are based on a connection of higher categories to "directed spaces". Directed spaces are locally modelled on manifold diagrams, which are stratifications of…

Category Theory · Mathematics 2023-03-21 Christoph Dorn

We investigate the homological behaviour of compactly generated triangulated categories under separable extensions. We show that homological invariants (finiteness of global dimension, gorensteinness and regularity) are preserved under such…

Representation Theory · Mathematics 2026-04-21 Miltiadis Karakikes , Panagiotis Kostas

We extend \cite{G} to the nonsemisimple case. We define and study exact factorizations $\B=\A\bullet \C$ of a finite tensor category $\B$ into a product of two tensor subcategories $\A,\C\subset \B$, and relate exact factorizations of…

Quantum Algebra · Mathematics 2022-02-17 Tathagata Basak , Shlomo Gelaki

This paper explores the restriction behavior of silting-induced $t$-structures and co-$t$-structures on triangulated categories endowed with metrics. For compactly generated triangulated categories admitting small coproducts, silting…

Category Theory · Mathematics 2026-04-30 Wei Hu , Ziheng Liu

We survey the basics of homological algebra in exact categories in the sense of Quillen. All diagram lemmas are proved directly from the axioms, notably the five lemma, the 3 x 3-lemma and the snake lemma. We briefly discuss exact functors,…

History and Overview · Mathematics 2009-04-22 Theo Buehler

We apply the Auslander-Buchweitz approximation theory to show that the Iyama and Yoshino's subfactor triangulated category can be realized as a triangulated quotient. Applications of this realization go in three directions. Firstly, we…

Representation Theory · Mathematics 2020-04-01 Zhenxing Di , Zhongkui Liu , Jiaqun Wei

We study some representations of symmetric groups arising from a certain ideal in the coordinate ring of affine n-space. Our results give graded and representation-theoretic enhancements of sequence 337 of the Online Encyclopaedia of…

Commutative Algebra · Mathematics 2024-09-17 Nsibiet E. Udo , Praise Adeyemo , Balazs Szendroi , Stavros Argyrios Papadakis

For a category $\mathcal E$ with finite limits and well-behaved countable coproducts, we construct a model structure, called the effective model structure, on the category of simplicial objects in $\mathcal E$, generalising the Kan--Quillen…

Category Theory · Mathematics 2022-11-11 Nicola Gambino , Simon Henry , Christian Sattler , Karol Szumiło

To any triangulated category with tensor product $(K,\otimes)$, we associate a topological space $Spc(K,\otimes)$, by means of thick subcategories of $K$, a la Hopkins-Neeman-Thomason. Moreover, to each open subset $U$ of $Spc(K,\otimes)$,…

Algebraic Geometry · Mathematics 2015-01-13 Paul Balmer

We develop the basic theory of covers and envelopes in proto-exact categories. As an application, we prove the existence of enough injectives for categories of Banach modules over arbitrary Banach rings.

Category Theory · Mathematics 2026-03-10 Jack Kelly

We apply the notion of a full convex subcategory to a wide range of algebras including tilted, quasi-tilted, shod, weakly shod, left and right glued, laura, simply connected, strongly simply connected, left supported, and cluster-tilted. In…

Representation Theory · Mathematics 2020-06-30 Stephen Zito

We define the triangulated category of relative singularities of a closed subscheme in a scheme. When the closed subscheme is a Cartier divisor, we consider matrix factorizations of the related section of a line bundle, and their analogues…

Category Theory · Mathematics 2015-07-07 Alexander I. Efimov , Leonid Positselski

A notion of mutation of subcategories in a right triangulated category is defined in this paper. When (Z,Z) is a D-mutation pair in a right triangulated category C, the quotient category Z/D carries naturally a right triangulated structure.…

Representation Theory · Mathematics 2019-02-21 Yu Liu , Bin Zhu

In this paper, we introduce and study relative phantom morphisms in extriangulated categories defined by Nakaoka and Palu. Then using their properties, we show that if $(\C,\E,\s)$ is an extriangulated category with enough injective objects…

Representation Theory · Mathematics 2017-02-15 Tiwei Zhao , Zhaoyong Huang

Let $\mathcal{X}$ be a resolving and contravariantly finite subcategory of $\rm{mod}\mbox{-}\Lambda$, the category of finitely generated right $\Lambda$-modules. We associate to $\mathcal{X}$ the subcategory…

Representation Theory · Mathematics 2019-10-10 Rasool Hafezi , Intan Muchtadi-Alamsyah