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Stable short exact sequences and the maximal exact structure of an additive category

Wolfgang Rump (2015)

Fundamenta Mathematicae

It was recently proved that every additive category has a unique maximal exact structure, while it remained open whether the distinguished short exact sequences of this canonical exact structure coincide with the stable short exact sequences. The question is answered by a counterexample which shows that none of the steps to construct the maximal exact structure can be dropped.

Stable tubes in extriangulated categories

Li Wang, Jiaqun Wei, Haicheng Zhang (2022)

Czechoslovak Mathematical Journal

Let 𝒳 be a semibrick in an extriangulated category. If 𝒳 is a τ -semibrick, then the Auslander-Reiten quiver Γ ( ( 𝒳 ) ) of the filtration subcategory ( 𝒳 ) generated by 𝒳 is 𝔸 . If 𝒳 = { X i } i = 1 t is a τ -cycle semibrick, then Γ ( ( 𝒳 ) ) is 𝔸 / τ 𝔸 t .

Stacks of group representations

Paul Balmer (2015)

Journal of the European Mathematical Society

We start with a small paradigm shift about group representations, namely the observation that restriction to a subgroup can be understood as an extension-of-scalars. We deduce that, given a group G , the derived and the stable categories of representations of a subgroup H can be constructed out of the corresponding category for G by a purely triangulated-categorical construction, analogous to étale extension in algebraic geometry. In the case of finite groups, we then use descent methods to investigate...

(Strongly) Gorenstein injective modules over upper triangular matrix Artin algebras

Chao Wang, Xiao Yan Yang (2017)

Czechoslovak Mathematical Journal

Let Λ = A M 0 B be an Artin algebra. In view of the characterization of finitely generated Gorenstein injective Λ -modules under the condition that M is a cocompatible ( A , B ) -bimodule, we establish a recollement of the stable category Ginj ( Λ ) ¯ . We also determine all strongly complete injective resolutions and all strongly Gorenstein injective modules over Λ .

Subcategories of the derived category and cotilting complexes

Aslak Bakke Buan (2001)

Colloquium Mathematicae

We show that there is a one-to-one correspondence between basic cotilting complexes and certain contravariantly finite subcategories of the bounded derived category of an artin algebra. This is a triangulated version of a result by Auslander and Reiten. We use this to find an existence criterion for complements to exceptional complexes.

Suite spectrale du coniveau et t -structure homotopique

Frédéric Déglise (2014)

Annales de la faculté des sciences de Toulouse Mathématiques

Dans cette note, nous montrons que la suite spectrale du coniveau associée à un spectre motivique sur un corps parfait coïncide avec sa suite spectrale d’hypercohomologie pour la t-structure homotopique.

Sur les quasi-limites

Syméon Bozapalides (1976)

Cahiers de Topologie et Géométrie Différentielle Catégoriques

Sur l’homologie des groupes orthogonaux et symplectiques à coefficients tordus

Aurélien Djament, Christine Vespa (2010)

Annales scientifiques de l'École Normale Supérieure

On calcule dans cet article l’homologie stable des groupes orthogonaux et symplectiques sur un corps fini k à coefficients tordus par un endofoncteur usuel F des k -espaces vectoriels (puissance extérieure, symétrique, divisée...). Par homologie stable, on entend, pour tout entier naturel i , les colimites des espaces vectoriels H i ( O n , n ( k ) ; F ( k 2 n ) ) et H i ( Sp 2 n ( k ) ; F ( k 2 n ) ) — dans cette situation, la stabilisation (avec une borne explicite en fonction de i et F ) est un résultat classique de Charney. Tout d’abord, nous donnons un cadre...

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