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Strongly 𝒲 -Gorenstein modules

Husheng Qiao, Zongyang Xie (2013)

Czechoslovak Mathematical Journal

Let 𝒲 be a self-orthogonal class of left R -modules. We introduce a class of modules, which is called strongly 𝒲 -Gorenstein modules, and give some equivalent characterizations of them. Many important classes of modules are included in these modules. It is proved that the class of strongly 𝒲 -Gorenstein modules is closed under finite direct sums. We also give some sufficient conditions under which the property of strongly 𝒲 -Gorenstein module can be inherited by its submodules and quotient modules....

Strongly groupoid graded rings and cohomology

Patrik Lundström (2006)

Colloquium Mathematicae

We interpret the collection of invertible bimodules as a groupoid and call it the Picard groupoid. We use this groupoid to generalize the classical construction of crossed products to what we call groupoid crossed products, and show that these coincide with the class of strongly groupoid graded rings. We then use groupoid crossed products to obtain a generalization from the group graded situation to the groupoid graded case of the bijection from a second cohomology group, defined by the grading...

Structuration cognitive et logique intrinsèque

Pascal Boldini (1993)

Mathématiques et Sciences Humaines

À travers l'étude d'un modèle de représentation des connaissances comme catégorie de faisceaux de traits localement définis ; ce texte montre que la théorie des topoï permet de décrire formellement l'émergence d'une logique intrinsèque à partir d'une approche relationnelle, qu'elle soit structurale ou cognitive. On peut alors caractériser mathématiquement le défaut d'intensionnalité des modèles classiques, et montrer qu'une solution est dans la mathématisation de structures entièrement relationnelles....

Structure theory for the group algebra of the symmetric group, with applications to polynomial identities for the octonions

Murray R. Bremner, Sara Madariaga, Luiz A. Peresi (2016)

Commentationes Mathematicae Universitatis Carolinae

This is a survey paper on applications of the representation theory of the symmetric group to the theory of polynomial identities for associative and nonassociative algebras. In §1, we present a detailed review (with complete proofs) of the classical structure theory of the group algebra 𝔽 S n of the symmetric group S n over a field 𝔽 of characteristic 0 (or p > n ). The goal is to obtain a constructive version of the isomorphism ψ : λ M d λ ( 𝔽 ) 𝔽 S n where λ is a partition of n and d λ counts the standard tableaux of shape λ ....

Structures d’asphéricité, foncteurs lisses, et fibrations

Georges Maltsiniotis (2005)

Annales mathématiques Blaise Pascal

Le but de cet article est de généraliser la théorie des foncteurs lisses de Grothendieck afin d’inclure dans ce cadre la théorie des catégories fibrées. On obtient en particulier une nouvelle caractérisation des catégories fibrées.

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.

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