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Related papers: A construction of 2-cofiltered bilimits of topoi

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A locally connected topos is a Galois topos if the Galois objects generate the topos. We show that the full subcategory of Galois objects in any connected locally connected topos is an inversely 2-filtered 2-category, and as an application…

Category Theory · Mathematics 2008-01-03 Eduardo J. Dubuc

We define the notion of 2-filtered 2-category and give an explicit construction of the bicolimit of a category valued 2-functor. A category considered as a trivial 2-category is 2-filtered if and only if it is a filtered category, and our…

Category Theory · Mathematics 2021-03-17 Eduardo J. Dubuc , Ross Street

Given a 2-category $\mathcal{A}$, a $2$-functor $\mathcal{A} \overset {F} {\longrightarrow} \mathcal{C}at$ and a distinguished 1-subcategory $\Sigma \subset \mathcal{A}$ containing all the objects, a $\sigma$-cone for $F$ (with respect to…

Category Theory · Mathematics 2018-03-21 M. E. Descotte , E. J. Dubuc , M. Szyld

We prove that a (lax) bilimit of a 2-functor is characterized by the existence of a limiting contraction in the 2-category of (lax) cones over the diagram. We also investigate the notion of bifinal object and prove that a (lax) bilimit is a…

Category Theory · Mathematics 2022-04-27 Andrea Gagna , Yonatan Harpaz , Edoardo Lanari

We develop a 2-dimensional version of accessibility and presentability compatible with the formalism of flat pseudofunctors. First we give prerequisites on the different notions of 2-dimensional colimits, filteredness and cofinality; in…

Category Theory · Mathematics 2025-08-05 Ivan Di Liberti , Axel Osmond

Pseudocolimits are formal gluing constructions that combine objects in a category indexed by a pseudofunctor. When the objects are categories and the domain of the pseudofunctor is small and filtered it has been known since Exppose 6 in…

Category Theory · Mathematics 2024-07-30 Deni Salja

Like categories, small 2-categories have well-understood classifying spaces. In this paper, we deal with homotopy types represented by 2-diagrams of 2-categories. Our results extend to homotopy colimits of 2-functors lower categorical…

Category Theory · Mathematics 2015-04-24 A. M. Cegarra , B. A. Heredia

We compare the colimit and 2-colimit of strict 2-functors in the 2-category of groupoids, over a certain type of posets. These posets are of special importance, as they correspond to coverings of a topological space. The main result of this…

Category Theory · Mathematics 2023-05-10 Ilia Pirashvili

We establish a bi-equivalence between the bi-category of topoi with enough points and a localisation of a bi-subcategory of topological groupoids

Category Theory · Mathematics 2026-03-17 Joshua Wrigley

We provide a complete set of identities for the symmetric monoidal category, TOF, generated by the Toffoli gate and computational ancillary bits. We do so by demonstrating that the functor which evaluates circuits on total points, is an…

Logic in Computer Science · Computer Science 2019-01-30 J. R. B. Cockett , Cole Comfort

We extend Deligne's original argument showing that locally coherent topoi have enough points, clarified using collage diagrams. We show that our refinement of Deligne's technique can be adapted to recover every existing result of this kind,…

Category Theory · Mathematics 2024-07-08 Ivan Di Liberti , Morgan Rogers

We study four types of (co)cartesian fibrations of $\infty$-bicategories over a given base $\mathcal{B}$, and prove that they encode the four variance flavors of $\mathcal{B}$-indexed diagrams of $\infty$-categories. We then use this…

Algebraic Topology · Mathematics 2021-03-11 Andrea Gagna , Yonatan Harpaz , Edoardo Lanari

The contributions of this paper are twofold. Within the framework of Grothendieck's fibrational category theory, we present a web of fundamental 2-adjunctions surrounding the formation of the category of all small diagrams in a given…

Category Theory · Mathematics 2021-03-09 George Peschke , Walter Tholen

We construct classifying $\infty$-topoi by showing that the $(\infty,2)$-category of topoi has weighted limits. We show that several prestacks of interest have a classifying topos, including the prestack of spectra.

Category Theory · Mathematics 2026-01-29 Ivan Di Liberti , Nicholas Meadows

We show that there are infinitely many distinct closed classes of colimits (in the sense of the Galois connection induced by commutation of limits and colimits in Set) which are intermediate between the class of pseudo-filtered colimits and…

Category Theory · Mathematics 2015-05-06 Marie Bjerrum , Peter Johnstone , Tom Leinster , William F. Sawin

The closure of chains of embedding-projection pairs (ep-pairs) under bilimits in some categories of predomains and domains is standard and well-known. For instance, Scott's $D_\infty$ construction is well-known to produce directed bilimits…

Logic in Computer Science · Computer Science 2022-02-18 Jonathan Sterling

In this paper we go into the study of 2-limits and 2-colimits in the 2-category CAT the category of small categories. More precisely we show the commutation of filtered 2-colimits and finite 2-limits. It is a generalization of a classical…

Category Theory · Mathematics 2009-04-10 Delphine Dupont

In this expository paper we explain in detail how to construct bicategorical colimits of several kinds of tensor categories, for example essentially small finitely cocomplete K-linear tensor categories. The constructions are direct and…

Category Theory · Mathematics 2020-01-29 Martin Brandenburg

We arrange morphisms and comorphisms of sites as the horizontal and vertical cells of a double category of sites; using the formalism of extensions and restrictions of presheaves, we explains how one can define a sheafification double…

Category Theory · Mathematics 2025-05-14 Olivia Caramello , Axel Osmond

We present some constructions of limits and colimits in pro-categories. These are critical tools in several applications. In particular, certain technical arguments concerning strict pro-maps are essential for a theorem about \'etale…

Category Theory · Mathematics 2007-05-23 Daniel C. Isaksen
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