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In this paper we study categorical properties of the category of abelian hypergroups that leads to the notion of hyper (almost) preadditive and hyper (almost) abelian categories. Our goal is to create a path towards a general theory of…

Category Theory · Mathematics 2025-09-11 Kaique Matias de Andrade Roberto , Ana Luiza Tenório

This paper considers non-Abelian homology groups of a group diagram introduced as homotopy groups of a simplicial change. We prove a theorem stating that the non-Abelian homology groups of a group diagram are isomorphic to the homotopy…

Algebraic Topology · Mathematics 2026-05-11 Ahmet A. Husainov

In this paper we study non-abelian extensions of a Lie group $G$ modeled on a locally convex space by a Lie group $N$. The equivalence classes of such extension are grouped into those corresponding to a class of so-called smooth outer…

Group Theory · Mathematics 2007-05-23 Karl-Hermann Neeb

We prove a constructive existence theorem for abelian envelopes of non-abelian monoidal categories. This establishes a new tool for the construction of tensor categories. As an example we obtain new proofs for the existence of several…

Category Theory · Mathematics 2023-06-22 Kevin Coulembier

Using cohomological methods, we prove a criterion for the embedding of a group extension with abelian kernel into the split extension of a co-induced module. This generalises some earlier similar results. We also prove an assertion about…

Group Theory · Mathematics 2018-05-15 Andrei V. Zavarnitsine

We give a geometric model for a tube category in terms of homotopy classes of oriented arcs in an annulus with marked points on its boundary. In particular, we interpret the dimensions of extension groups of degree 1 between indecomposable…

Representation Theory · Mathematics 2020-12-21 Karin Baur , Bethany Marsh

We construct an embedding G of the category of graphs into the category of abelian groups such that for graphs X and Y we have Hom(GX,GY)=Z[Hom(X,Y)], the free abelian group whose basis is the set Hom(X,Y). The isomorphism is functorial in…

Category Theory · Mathematics 2014-03-20 Adam J. Przezdziecki

Given an abelian variety over a field with a discrete valuation, Grothendieck defined a certain open normal subgroup of the absolute inertia group. This subgroup encodes information on the extensions over which the abelian variety acquires…

alg-geom · Mathematics 2008-02-03 A. Silverberg , Yu. G. Zarhin

It is shown that any localisation of triangulated categories induces (up to an equivalence) a localisation of abelian categories when one passes to their abelianisations. From this one obtains for any enlargement of Grothendieck universes…

Category Theory · Mathematics 2025-03-11 Henning Krause

The distributive property can be studied through bilinear maps and various morphisms between these maps. The adjoint-morphisms between bilinear maps establish a complete abelian category with projectives and admits a duality. Thus the…

Category Theory · Mathematics 2012-05-04 James B. Wilson

The class of locally compact near abelian groups is introduced and investigated as a class of metabelian groups formalizing and applying the concept of scalar multiplication. The structure of locally compact near abelian groups and its…

Group Theory · Mathematics 2017-02-14 Karl H. Hofmann , Wolfgang Herfort , Francesco G. Russo

We introduce abelian framed bicategories, which are particular framed bicategories that are locally abelian, and show that they are suitable for developing homology and cohomology theories for directed structures. This means in particular…

Category Theory · Mathematics 2026-02-05 Augustin Albert , Jérémy Dubut , Eric Goubault

Through abelian categories, homological lemmas for modules admit a self-dual treatment, where half of the proof of a lemma is sufficient to prove the full lemma. In this paper, we show how the context of a `noetherian form', recently…

The notion of gluing of abelian categories was introduced by Kazhdan and Laumon in an attempt of another geometric construction of representations of finite Chevalley groups; the approach was later developed by Polishchuk and Braverman. We…

Representation Theory · Mathematics 2009-09-04 Roman Bezrukavnikov , Alexander Braverman , Leonid Positselskii

We show how monoidal adjunctions can be used to prove the existence of monoidal abelian envelopes of pseudo-tensor categories, in particular, those admitting a combinatorial description with certain properties. We derive concrete general…

Representation Theory · Mathematics 2026-03-03 Johannes Flake , Robert Laugwitz , Sebastian Posur

Let $\mathcal A$ be a locally noetherian Grothendieck category. In this paper, we study subcategories of $\mathcal A$ using subsets of the Rosenberg spectrum $\mathfrak Spec(\mathcal A)$. Along the way, we also develop results in local…

Category Theory · Mathematics 2023-02-22 Abhishek Banerjee

For any graded commutative noetherian ring, where the grading group is abelian and where commutativity is allowed to hold in a quite general sense, we establish an inclusion-preserving bijection between, on the one hand, the twist-closed…

Category Theory · Mathematics 2012-11-07 Ivo Dell'Ambrogio , Greg Stevenson

Cohomology of a topological space with coefficients in stacks of abelian 2-groups is considered. A 2-categorical analog of the theorem of Grothendieck is proved, relating cohomology of the space with coefficients in a 2-stage spectrum and…

Algebraic Topology · Mathematics 2011-06-30 Mamuka Jibladze , Teimuraz Pirashvili

We develop a functorial approach to the study of $n$-abelian categories by reformulating their axioms in terms of their categories of finitely presented functors. Such an approach allows the use of classical homological algebra and…

Category Theory · Mathematics 2025-10-14 Vitor Gulisz

Algebraic structures such as monoids, groups, and categories can be formulated within a category using commutative diagrams. In many common categories these reduce to familiar cases. In particular, group objects in Grp are abelian groups,…

Category Theory · Mathematics 2007-05-23 Magnus Forrester-Barker