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Related papers: $n$-abelian and $n$-exact categories

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From the viewpoint of semi-abelian homology, some recent results on homology of Leibniz n-algebras can be explained categorically. In parallel with these results, we develop an analogous theory for Lie n-algebras. We also consider the…

Algebraic Topology · Mathematics 2011-03-16 Jose Manuel Casas , Emzar Khmaladze , Manuel Ladra , Tim Van der Linden

Recollements of abelian categories are used as a basis of a homological and recursive approach to quasi-hereditary algebras. This yields a homological proof of Dlab and Ringel's characterisation of idempotent ideals occuring in heredity…

Representation Theory · Mathematics 2018-04-25 Nan Gao , Steffen Koenig , Chrysostomos Psaroudakis

We use functorial methods to define and study $0$-abelian categories, which we propose to be the case $n = 0$ of Jasso's $n$-abelian categories. In particular, we define a bifunctor for $0$-abelian categories with enough injectives or…

Category Theory · Mathematics 2025-09-30 Vitor Gulisz

We define abelian extensions of algebras in congruence-modular varieties. The theory is sufficiently general that it includes, in a natural way, extensions of R-modules for a ring R. We also define a cohomology theory, which we call clone…

Rings and Algebras · Mathematics 2007-05-23 William H. Rowan

Neeman shows that the completion of a triangulated category with respect to a good metric yields a triangulated category. We compute completions of discrete cluster categories with respect to metrics induced by internal t-structures. In…

Representation Theory · Mathematics 2024-09-24 Charley Cummings , Sira Gratz

We define the Grothendieck group of an n-angulated category and show that for odd n its properties are as in the special case of n=3, i.e. the triangulated case. In particular, its subgroups classify the dense and complete n-angulated…

Category Theory · Mathematics 2012-05-28 Petter Andreas Bergh , Marius Thaule

This paper studies abelian categories that can be decomposed into smaller abelian categories via iterated recollements - such a decomposition we call a stratification. Examples include the categories of (equivariant) perverse sheaves and…

Representation Theory · Mathematics 2025-06-23 Giulian Wiggins

Following ideas of Lawvere and Linton we prove that classical varieties are precisely the exact categories with a varietal generator. This means a strong generator which is abstractly finite and regularly projective. An analogous…

Category Theory · Mathematics 2024-02-23 Jiri Adamek

We investigate relative cohomology functors on subcategories of abelian categories via Auslander-Buchweitz approximations and the resulting strict resolutions. We verify that certain comparison maps between these functors are isomorphisms…

K-Theory and Homology · Mathematics 2007-06-27 Sean Sather-Wagstaff , Tirdad Sharif , Diana White

An example of a cocomplete abelian category that is not complete is constructed.

Category Theory · Mathematics 2018-05-29 Jeremy Rickard

The cluster category is a triangulated category introduced for its combinatorial similarities with cluster algebras. We prove that a cluster algebra A of finite type can be realized as a Hall algebra, called the exceptional Hall algebra, of…

Representation Theory · Mathematics 2007-05-23 Philippe Caldero , Bernhard Keller

We show that a well behaved Noetherian, finite dimensional, stable, monoidal model category is equivalent to a model built from categories of modules over completed rings in an adelic fashion. For abelian groups this is based on the Hasse…

Algebraic Topology · Mathematics 2020-07-28 J. P. C. Greenlees , Scott Balchin

This article introduces Hilbert $*$-categories: an abstraction of categories with similar algebraic and analytic properties to the categories of real, complex, and quaternionic Hilbert spaces and bounded linear maps. Other examples include…

Category Theory · Mathematics 2025-12-09 Matthew Di Meglio , Chris Heunen

In this paper we suggest a new general formalism for studying the invariants of polyhedra and manifolds comming from the theory of von Neumann algebras. First, we examine generality in which one may apply the construction of the extended…

dg-ga · Mathematics 2008-02-03 Michael Farber

In this note, we propose a generalisation of G. Janelidze's notion of an ideally exact category beyond the Barr exact setting. We define an ideally regular category as a regular, Bourn protomodular category with finite coproducts in which…

Category Theory · Mathematics 2026-03-03 Sandra Mantovani , Mariano Messora

We prove that the category of commutative Hopf algebras over a field $k$ is co-semi-abelian. Consequently, the category of affine group $k$-schemes is semi-abelian. We establish coregularity by identifying the orthogonal factorization…

Category Theory · Mathematics 2026-02-25 David Forsman

We prove basic statements about the Hermitian K-theory of exact form categories with weak equivalences. Notably, we extend a quadratic functor with values in abelian groups from an exact category to its category of bounded chain complexes…

K-Theory and Homology · Mathematics 2024-11-14 Marco Schlichting

We define model category structures on the category of chain complexes over a Grothendieck abelian category depending on the choice of a generating family, and we study their behaviour with respect to tensor products and stabilization. This…

Category Theory · Mathematics 2007-12-21 Denis-Charles Cisinski , Frédéric Déglise

We introduce the notions of proto-complete, complete, complete* and strong-complete objects in pointed categories. We show under mild conditions on a pointed exact protomodular category that every proto-complete (respectively complete)…

Category Theory · Mathematics 2021-02-22 James Richard Andrew Gray

We study when the stable category of an abelian category modulo a full additive subcategory is balanced and, in case the subcategory is functorially finite, we study a weak version of balance. Precise necessary and sufficient conditions are…

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