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Related papers: Left-exact Mittag-Leffler functors of modules

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Let $\mathcal{C}$ be a small category and let $R$ be a dg-representation of the category $\mathcal{C}$, that is, a pseudofunctor from a small category to the category of small dg $k$-categories, where $k$ is a commutative unital ring. In…

Representation Theory · Mathematics 2025-05-30 Mawei Wu

We consider $\,R-$modules as functors in the following way: if $\,M\,$ is a (left) $R$-module, let $\,\mathcal M\,$ be the functor of $\,\mathcal R-$modules defined by $\,\mathcal M(S) := S \otimes_R M\,$ for every $\,R-$algebra $\,S$. With…

Rings and Algebras · Mathematics 2018-06-27 Adrián Gordillo-Merino , José Navarro , Pedro Sancho

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

This survey article is intended as an introduction to the recent categorical classification theorems of the three authors, restricting to the special case of the category of modules for a finite group.

Representation Theory · Mathematics 2011-02-15 Dave Benson , Srikanth B. Iyengar , Henning Krause

We prove that the categories of Gelfand-Zeitlin modules of $\mathfrak{g}=\mathfrak{gl}_n$ and Whittaker modules associated with a semi-simple complex finite-dimensional algebra $\mathfrak{g}$ are extension full in the category of all…

Representation Theory · Mathematics 2015-02-25 Kevin Coulembier , Volodymyr Mazorchuk

In this article we extend evaluations of the Kauffman bracket on regular isotopy classes of knots and links to a variety of functors defined on the category of framed tangles. We show that many such functors exist, and that they correspond…

Geometric Topology · Mathematics 2007-05-23 John Armstrong

A pair of adjoint functors $(F,G)$ is called a Frobenius pair of the second type if $G$ is a left adjoint of $\beta F\alpha$ for some category equivalences $\alpha$ and $\beta$. Frobenius ring extensions of the second kind provide examples…

Rings and Algebras · Mathematics 2007-05-23 S. Caenepeel , E. De Groot , G. Militaru

In this note we introduce and study basic properties of two types of modules over a commutative noetherian ring $R$ of positive prime characteristic. The first is the category of modules of finite $F$-type. These objects include reflexive…

Commutative Algebra · Mathematics 2016-03-02 Hailong Dao , Tony Se

For each recollement of triangulated categories, there is an epivalence between the middle category and the comma category associated to a triangle functor from the category on the right to the category on the left. For a morphic…

Rings and Algebras · Mathematics 2022-09-21 Xiao-Wu Chen , Jue Le

In the theory of operads we consider functors of generalized symmetric powers defined by sums of coinvariant modules under actions of symmetric groups. One observes classically that the construction of symmetric functors provides an…

Algebraic Topology · Mathematics 2009-02-25 Benoit Fresse

It was conjectured by Gorsky, Hogancamp, Mellit, and Nakagane that the left and right adjoints of the parabolic induction functor between homotopy categories of Soergel bimodules associated to a finite Coxeter group are related by the…

Representation Theory · Mathematics 2026-04-08 Colton Sandvik

Let $(\mathfrak{C},\mathbb{E},\mathfrak{s})$ be an Ext-finite, Krull-Schmidt and $k$-linear extriangulated category with $k$ a commutative artinian ring. We define an additive subcategory $\mathfrak{C}_r$ (respectively, $\mathfrak{C}_l$) of…

Representation Theory · Mathematics 2020-05-15 Tiwei Zhao , Lingling Tan , Zhaoyong Huang

We study linear versions of Reedy categories in relation with finite dimensional algebras and abelian model structures. We prove that, for a linear Reedy category $\mathcal{C}$ over a field, the category of left $\mathcal{C}$--modules…

Representation Theory · Mathematics 2025-09-23 Georgios Dalezios , Jan Stovicek

In this article, we will show that the category of biset functors can be regarded as a reflective monoidal subcategory of the category of Mackey functors on the 2-category of finite groupoids. This reflective subcategory is equivalent to…

Category Theory · Mathematics 2016-01-26 Hiroyuki Nakaoka

Reflexive functors of modules naturally appear in Algebraic Geometry. In this paper we define a wide and elementary family of reflexive functors of modules, closed by tensor products and homomorphisms, in which Algebraic Geometry can be…

Algebraic Geometry · Mathematics 2015-11-16 Pedro Sancho

For a variety X which admits a Cox ring we introduce a functor from the category of quasi-coherent sheaves on $X$ to the category of graded modules over the homogeneous coordinate ring of $X$. We show that this functor is right-adjoint to…

Algebraic Geometry · Mathematics 2017-06-27 Markus Perling

Let $A$ be a DG algebra with a trivial differential over a commutative unital ring. This paper investigates the image of the totaling functor, defined from the category of complexes of graded $A$-modules to the category of DG $A$-modules.…

Category Theory · Mathematics 2013-08-16 Kristen A. Beck

The bicategory of Landau-Ginzburg models denoted by LGK possesses adjoints and this helps in explaining a certain duality that exists in the setting of Landau-Ginzburg models in terms of some specified relations. The construction of LGK is…

Category Theory · Mathematics 2024-02-05 Yves Baudelaire Fomatati

Derived equivalences and t-structures are closely related. We use realisation functors associated to t-structures in triangulated categories to establish a derived Morita theory for abelian categories with a projective generator or an…

Representation Theory · Mathematics 2017-07-26 Chrysostomos Psaroudakis , Jorge Vitória

G\'en\'eralisant un article de Pirashvili, nous caract\'erisons les petites cat\'egories additives A telles que l'inclusion dans la cat\'egorie des foncteurs de A vers les groupes ab\'eliens de la sous-cat\'egorie pleine des foncteurs…

Algebraic Topology · Mathematics 2015-06-12 Aurélien Djament