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Related papers: Cosheafification

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Given a small simplicial category $\C$ whose underlying ordinary category is equipped with a Grothendieck topology $\tau$, we construct a model structure on the category of simplicially enriched presheaves on $\C$ where the weak…

Algebraic Topology · Mathematics 2018-11-20 Georgios Raptis , Florian Strunk

In this paper the cosheaf homology is investigated from different viewpoints: the behavior under site morphisms, connections with Cech homology via spectral sequences, and description of cosheaf homology using hypercoverings. It is proved…

Algebraic Topology · Mathematics 2025-04-24 Andrei V. Prasolov

We study the relationship between presheaf constructions and free cocompletions in the context of formal category theory, elucidating the coincidence between the two concepts in familiar settings. We show that, in a virtual equipment…

Category Theory · Mathematics 2026-04-27 Nathanael Arkor , Dylan McDermott

We prove a sheaf-theoretic derived-category generalization of Greenlees-May duality (a far-reaching generalization of Grothendieck's local duality theorem): for a quasi-compact separated scheme X and a "proregular" subscheme Z---for…

alg-geom · Mathematics 2008-02-03 Leovigildo Alonso , Ana Jeremías , Joseph Lipman

On a Weinstein manifold, we define a constructible co/sheaf of categories on the skeleton. The construction works with arbitrary coefficients, and depends only on the homotopy class of a section of the Lagrangian Grassmannian of the stable…

Symplectic Geometry · Mathematics 2017-07-25 Vivek Shende

For a coherent filtered D-module we show that the dual of each graded piece over the structure sheaf is isomorphic to a certain graded piece of the ring-theoretic local cohomology complex of the graded quotient of the dual of the filtered…

Algebraic Geometry · Mathematics 2014-07-02 Morihiko Saito , Christian Schnell

Let $k$ be a non-archimedean complete valued field and let X be a smooth Berkovich analytic $k$-curve. Let $F$ be a finite locally constant \'{e}tale sheaf on $k$ whose torsion is prime to the residue characteristic. We denote by $|X|$ the…

Algebraic Geometry · Mathematics 2007-05-23 Antoine Ducros

For a finite group $G$, we compute the algebraic $K$-theory of the category of equivariant sheaves on a locally compact Hausdorff $G$-space, generalizing a result of Efimov, and determine the equivariant $E$-theory of the $C^*$-algebra of…

K-Theory and Homology · Mathematics 2026-04-10 Guido Arnone , Devarshi Mukherjee , Thomas Nikolaus

Given any additive category $\mathcal{C}$ with split idempotents, pseudokernels and pseudocokernels, we show that a subcategory $\mathcal{B}$ is coreflective if, and only if, it is precovering, closed under direct summands and each morphism…

Category Theory · Mathematics 2022-10-04 Manuel Cortés-Izurdiaga , Septimiu Crivei , Manuel Saorín

We provide an explicit characterization of the covariant isotropy group of any Grothendieck topos, i.e. the group of (extended) inner automorphisms of any sheaf over a small site. As a consequence, we obtain an explicit characterization of…

Category Theory · Mathematics 2021-04-29 Jason Parker

In [CS01, Page 109] Grothendieck sketches the construction of a complex J_*(X) or commutative pro-algebraic groups, associated to a smooth variety X, and for which each J_i(X) is a product of local factors called the local generalized…

Algebraic Geometry · Mathematics 2026-02-24 Bertrand Toen

The purpose of this paper is to explain why the functor that sends a stratified topological space $S$ to the $\infty$-category of constructible (hyper)sheaves on $S$ with coefficients in a large class of presentable $\infty$categories is…

Algebraic Topology · Mathematics 2022-09-09 Peter J. Haine , Mauro Porta , Jean-Baptiste Teyssier

We prove analogs of Whitehead's theorem (from algebraic topology) for both the Chow groups and for the Grothendieck group of coherent sheaves: a morphism between smooth projective varieties whose pushforward is an isomorphism on the Chow…

Algebraic Geometry · Mathematics 2021-03-04 Eoin Mackall

Generalizations of the theorems of Eberlein and Grothendieck on the precompactness of subsets of function spaces are considered: if $X$ is a countably compact space and $C_p(X)$ is a space of continuous functions in the pointwise topology…

General Topology · Mathematics 2024-11-06 E. A. Reznichenko

The center $Z(\mathcal{A})$ of an abelian category $\mathcal{A}$ is the endomorphism ring of the identity functor on that category. A localizing subcategory of a Grothendieck category $\mathcal{C}$ is said to be stable if it is stable under…

Representation Theory · Mathematics 2022-10-25 Konstantin Ardakov , Peter Schneider

We compute the sheaf cohomology with constant $\mathbb{Z}_2$ coefficients of a concrete class of locally profinite sets of independent interest. We introduce $k$-sheer partitions to aid in constructions. It is also shown that questions of…

Logic · Mathematics 2026-04-14 Mark Schachner

The usual notion of a site fibred over a stack is expanded to a definition of a site C/A fibred over a presheaf of categories A. Presheaves of simplicial sets on the site fibred over a presheaf of categories A are contravariant enriched…

Algebraic Topology · Mathematics 2007-05-23 J. F. Jardine

This paper gives an introduction to homotopy descent, and its applications in algebraic $K$-theory computations for fields. On the \'etale site of a field, a fibrant model of a simplicial presheaf can be constructed from naive Galois…

Algebraic Geometry · Mathematics 2019-06-17 J. F. Jardine

With a model of a geometric theory in an arbitrary topos, we associate a site obtained by endowing a category of generalized elements of the model with a Grothendieck topology, which we call the antecedent topology. Then we show that the…

Category Theory · Mathematics 2021-04-13 Olivia Caramello , Axel Osmond

We give an elementary short proof of Grothendieck's base change theorem for the cohomology of flat coherent sheaves.

Algebraic Geometry · Mathematics 2013-12-30 Eduardo Tengan