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Related papers: Classification of Constructible Cosheaves

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We provide a generalization of the construction of a spectrum of a commutative ring as a locally ringed space, applicable to cone injectivity classes in general contexts, especially in locally finitely presentable categories. In its full…

Category Theory · Mathematics 2023-12-05 Jan Jurka , Tomáš Perutka , Lukáš Vokřínek

The aim of this note is threefold. The first is to obtain a simple characterization of relative constructible sheaves when the parameter space is projective. The second is to study the relative Fourier-Mukai for relative constructible…

Algebraic Geometry · Mathematics 2025-08-19 Luisa Fiorot , Teresa Monteiro Fernandes

We give a homotopy theoretic characterization of stacks on a site $\cC$ as the {\it homotopy sheaves} of groupoids on $\cC$. We use this characterization to construct a model category in which stacks are the fibrant objects. We compare…

Algebraic Topology · Mathematics 2007-08-20 Sharon Hollander

In this thesis we show how to use stack theory to glue description of the category of perverse sheaves P(X,S) on a stratified space (X,S). Hence we give new description of P(X,S) when X is locally C^n stratified by the stratification S…

Algebraic Geometry · Mathematics 2009-03-30 Delphine Dupont

We present a detailed introduction of the theory of constructible sheaf complexes in the complex algebraic and analytic setting. All concepts are illustrated by many interesting examples and relevant applications, while some important…

Algebraic Geometry · Mathematics 2021-06-03 Laurenţiu G. Maxim , Jörg Schürmann

We introduce the notion of a definable category--a category equivalent to a full subcategory of a locally finitely presentable category that is closed under products, directed colimits and pure subobjects. Definable subcategories are…

Category Theory · Mathematics 2016-12-13 Amit Kuber , Jiří Rosický

Recently, Cochran and Harvey defined torsion-free derived series of groups and proved an injectivity theorem on the associated torsion-free quotients. We show that there is a universal construction which extends such an injectivity theorem…

Geometric Topology · Mathematics 2007-05-23 Jae Choon Cha

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

One goal of applied category theory is to better understand networks appearing throughout science and engineering. Here we introduce "structured cospans" as a way to study networks with inputs and outputs. Given a functor $L \colon…

Category Theory · Mathematics 2020-11-11 John C. Baez , Kenny Courser

We look at homotopy-coherent diagrams of spaces (after Segal, Leitch, Vogt, Mather, Cordier) over a Grothendieck site; we call these ``flexible presheaves''. After some preliminary materiel, we define the ``flexible sheaf'' condition. This…

q-alg · Mathematics 2008-02-03 Carlos Simpson

We define the notion of {\em classifying space} of a topological stack and show that every topological stack \X has a classifying space X which is a topological space well-defined up to weak homotopy equivalence. Under a certain…

Algebraic Topology · Mathematics 2010-05-04 Behrang Noohi

Let $\mathcal C$ be a category with finite colimits, and let $(\mathcal E,\mathcal M)$ be a factorisation system on $\mathcal C$ with $\mathcal M$ stable under pushouts. Writing $\mathcal C;\mathcal M^{\mathrm{op}}$ for the symmetric…

Category Theory · Mathematics 2017-03-30 Brendan Fong

We develop a local-to-global formalism for constructing Calabi-Yau structures for global sections of constructible sheaves or cosheaves of categories. The required data - an isomorphism of the sheafified Hochschild homology with the…

Algebraic Geometry · Mathematics 2024-05-16 Vivek Shende , Alex Takeda

We show that constructible models of arbitrary complete continuous first-order theories are unique up to isomorphism.

Logic · Mathematics 2025-01-07 James E. Hanson

We introduce the notion of an accessible $\infty$-cosmos and prove that these include the basic examples of $\infty$-cosmoi and are stable under the main constructions. A consequence is that the vast majority of known examples of…

Category Theory · Mathematics 2022-12-14 John Bourke , Stephen Lack

Suppose $C$ is a smooth projective curve of genus 1 over a perfect field $F$, and $E$ is its Jacobian. In the case that $C$ has no $F$-rational points, so that $C$ and $E$ are not isomorphic, $C$ is an $E$-torsor with a class $\delta(C)\in…

Algebraic Geometry · Mathematics 2025-07-10 Niranjan Ramachandran , Jonathan Rosenberg

Finite \'etale covers of a connected scheme $X$ are parametrised by the \'etale fundamental group via the monodromy correspondence. This was generalised to an exodromy correspondence for constructible sheaves, first in the topological…

Algebraic Geometry · Mathematics 2024-10-10 Remy van Dobben de Bruyn

By looking at decidable quotients, a sufficient condition is provided to guarantee that (1) the full subcategory of decidable objects of a topos is an exponential ideal and that (2) the classical notion of connectedness for an object $X$…

Category Theory · Mathematics 2025-04-23 Enrique Ruiz Hernández , Pedro Solórzano

The notion of proof-net category defined in this paper is closely related to graphs implicit in proof nets for the multiplicative fragment without constant propositions of linear logic. Analogous graphs occur in Kelly's and Mac Lane's…

Category Theory · Mathematics 2007-05-23 K. Dosen , Z. Petric

In their article "Elementary construction of perverse sheaves", R.MacPherson and K. Vilonen show that on a Thom-Mather space X the category PervX of perverse sheaves is equivalent to the category C(F, G, T) whose objects are data of…

Algebraic Geometry · Mathematics 2011-03-23 Delphine Dupont