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Related papers: Cauchy Completeness, Lax Epimorphisms and Effectiv…

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We study effective descent $ \mathcal V $-functors for cartesian monoidal categories $ \mathcal V $ with finite limits. This study is carried out via the properties enjoyed by the $2$-functor $ \mathcal V \mapsto \mathsf{Fam}(\mathcal V) $,…

Category Theory · Mathematics 2024-01-15 Rui Prezado

In the paper where he defined the Cauchy completion of a $\mathscr{V}$-category, Lawvere also defined a condition on a $\mathscr{V}$-functor which made it analogous to a map of metric spaces whose image is topologically dense in its…

Category Theory · Mathematics 2025-07-11 Adrián Doña Mateo

We investigate the connection between left exact $\infty$-functors between finitely complete quasicategories and exact functors between fibration categories, describing a procedure to approximate flat $\infty$-functors of the former type by…

Category Theory · Mathematics 2026-02-20 El Mehdi Cherradi

Effective descent morphisms, originally defined in Grothendieck descent theory, form a class of special morphisms within a category. Essentially, an effective descent morphism enables bundles over its codomain to be fully described as…

Category Theory · Mathematics 2024-11-05 Fernando Lucatelli Nunes , Rui Prezado

Let $\mathsf{Ord} $ be the category of (pre)ordered sets. Unlike $\mathsf{Ord}/X$, whose behaviour is well-known, not much can be found in the literature about the lax comma 2-category $\mathsf{Ord} //X$. In this paper we show that the…

Category Theory · Mathematics 2023-11-13 Maria Manuel Clementino , Fernando Lucatelli Nunes

These notes explain some descent results for $\infty$-categories of sheaves on compact Hausdorff spaces and derive some consequences. Specifically, given a compactly assembled $\infty$-category $\mathcal{E}$, we show that the functor…

Algebraic Topology · Mathematics 2022-10-04 Peter J. Haine

Suppose we are given complex manifolds $X$ and $Y$ together with substacks $\mathcal{S}$ and $\mathcal{S}'$ of modules over algebras of formal deformation $\mathcal{A}$ on $X$ and $\mathcal{A}'$ on $Y$, respectively. Suppose also we are…

Algebraic Geometry · Mathematics 2013-01-10 Ana Rita Martins , Teresa Monteiro Fernandes , David Raimundo

We investigate the properties of lax comma categories over a base category $X$, focusing on topologicity, extensivity, cartesian closedness, and descent. We establish that the forgetful functor from $\mathsf{Cat}//X$ to $\mathsf{Cat}$ is…

Category Theory · Mathematics 2024-06-13 Maria Manuel Clementino , Fernando Lucatelli Nunes , Rui Prezado

We study a number of categorical quasi-uniform structures induced by functors. We depart from a category $\mathcal{C}$ with a proper $(\mathcal{E}, \mathcal{M})$-factorization system, then define the continuity of a $\mathcal{C}$-morphism…

Category Theory · Mathematics 2023-02-07 Minani Iragi , David Holgate

In this monograph we provide an in-depth and systematic study of pseudolimits of pseudofunctors $F:\mathscr{C}^{op} \to \mathfrak{Cat}$ in the $2$-category of categories where $\mathscr{C}$ is a $1$-category and use this to give an explicit…

Algebraic Geometry · Mathematics 2024-01-19 Geoff Vooys

Let $k$ be a field, $X$ a connected scheme proper over $k$, $D\subsetneq X$ an ample effective connected divisor, $x\in D(k)$. For Tannakian categories $\mathcal{C}_X$ and $\mathcal{C}_D$ whose objects consist of vector bundles on $X$ and…

Algebraic Geometry · Mathematics 2026-04-28 Lingguang Li , Niantao Tian

The constrained minimisers of convex integral functionals of the form $\mathscr F(v)=\int_\Omega F(\nabla^k v(x))\mathrm d x $ defined on Sobolev mappings $v\in \mathrm W^{k,1}_g(\Omega , \mathbb R^N )\cap K$, where $K$ is a closed convex…

Analysis of PDEs · Mathematics 2022-03-02 Lukas Koch , Jan Kristensen

Building on previous work, we study the splitting of idempotents in the category of extensions $\mathbb{E}\operatorname{-Ext}(\mathcal{C})$ associated to a pair $(\mathcal{C},\mathbb{E})$ of an additive category and a biadditive functor to…

Category Theory · Mathematics 2023-10-27 Raphael Bennett-Tennenhaus , Johanne Haugland , Mads Hustad Sandøy , Amit Shah

The fundamental construction underlying descent theory, the lax descent category, comes with a functor that forgets the descent data. We prove that, in any $2$-category $\mathfrak{A} $ with lax descent objects, the forgetful morphisms…

Category Theory · Mathematics 2021-05-21 Fernando Lucatelli Nunes

We study lax epimorphisms in 2-categories, with special attention to $\mathsf{Cat}$ and $\mathcal{V}$-$\mathsf{Cat}$. We show that any 2-category with convenient colimits has an orthogonal $LaxEpi$-factorization system, and we give a…

Category Theory · Mathematics 2023-11-13 Fernando Lucatelli Nunes , Lurdes Sousa

Expanding on the comprehensive factorization of functors internal to a category C, under fairly mild conditions on a monad T on C we establish that this orthogonal factorization system exists even in Burroni's category Cat(T) of (internal)…

Category Theory · Mathematics 2020-12-16 Walter Tholen , Leila Yeganeh

For a (possibly large) realized limit sketch $\mathcal{S}$ such that every $\mathcal{S}$-model is small in a suitable sense we show that the category of cocontinuous functors $\mathsf{Mod}(\mathcal{S}) \to \mathcal{C}$ into a cocomplete…

Category Theory · Mathematics 2023-09-11 Martin Brandenburg

As already mentioned by Lawvere in his 1973 paper, the characterisation of Cauchy completeness of metric spaces in terms of representability of adjoint distributors amounts to the idempotent-split property of an ordinary category when the…

Category Theory · Mathematics 2025-10-02 Dirk Hofmann , Walter Tholen

We study discrete opfibration classifiers in enhanced 2-categories and show how, under suitable hypotheses, such classifiers can be endowed with the structure of a (lax or pseudo-)T-algebra and classify strict discrete opfibrations in…

Category Theory · Mathematics 2026-05-07 Matteo Capucci , David Jaz Myers

We present a characterization of effective descent morphisms in the lax comma category $\mathsf{Ord}//X$ when $X$ is a locally complete ordered set, as well as in the antisymmetric setting.

Category Theory · Mathematics 2025-03-21 Maria Manuel Clementino , Rui Prezado
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