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Related papers: A Full and faithful Nerve for 2-categories

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We extend the notion of the nerve of a category for a small class of crossed simplicial groups, explicitly describing them using generators and relations. We do this by first considering a generalised bar construction of a group before…

Category Theory · Mathematics 2017-05-22 Scott Balchin

Given a simplicial complex and a collection of subcomplexes covering it, the nerve theorem, a fundamental tool in topological combinatorics, guarantees a certain connectivity of the simplicial complex when connectivity conditions on the…

Combinatorics · Mathematics 2019-07-30 Frédéric Meunier , Luis Montejano

Evidence is given for the correctness of the Joyal-Riehl-Verity construction of the homotopy bicategory of the $(\infty, 2)$-category of $(\infty, 1)$-categories; in particular, it is shown that the analogous construction using complete…

Category Theory · Mathematics 2013-11-05 Zhen Lin Low

Given a simplicial group G, there are two known classifying simplicial set constructions, the Kan classifying simplicial set Wbar G and Diag N G, where N denotes the dimensionwise nerve. They are known to be weakly homotopy equivalent. We…

Algebraic Topology · Mathematics 2011-03-31 Sebastian Thomas

We define and discuss lax and weighted colimits of diagrams in $\infty$-categories and show that the coCartesian fibration associated to a functor is given by its lax colimit. A key ingredient, of independent interest, is a simple…

Category Theory · Mathematics 2020-11-03 David Gepner , Rune Haugseng , Thomas Nikolaus

In this paper we study a 2-dimensional version of Quillen's homotopy category construction. Given a category $\mathscr{A}$ and a class of morphisms $\Sigma \subset \mathscr{A}$ containing the identities, we construct a 2-category…

Category Theory · Mathematics 2023-02-28 Eduardo J. Dubuc , Jaqueline Girabel

We use Kan injectivity to axiomatise concepts in the 2-category of topoi. We showcase the expressivity of this language through many examples, and we establish some aspects of the formal theory of Kan extension in this 2-category (pointwise…

Logic · Mathematics 2025-05-22 Ivan Di Liberti , Lingyuan Ye

In this paper, we introduce a cofibrant simplicial category that we call the free homotopy coherent adjunction and characterize its n-arrows using a graphical calculus that we develop here. The hom-spaces are appropriately fibrant, indeed…

Category Theory · Mathematics 2015-10-14 Emily Riehl , Dominic Verity

One can associate to any strict globular $\omega$-category three augmented simplicial nerves called the globular nerve, the branching and the merging semi-cubical nerves. If this strict globular $\omega$-category is freely generated by a…

Algebraic Topology · Mathematics 2007-05-23 Philippe Gaucher

Derivators, introduced independently by Grothendieck and Heller in the 1980s, provide a categorical framework for studying homotopy theory. They are based on the idea that, while the homotopy 1-category of a single model category or…

Category Theory · Mathematics 2025-12-12 Nicola Di Vittorio

We lay the foundations for a theory of quasi-categories in a monoidal category $\mathcal{V}$ replacing $\mathrm{Set}$, aimed at realising weak enrichment in the category $S\mathcal{V}$ of simplicial objects in $\mathcal{V}$. To accomodate…

Category Theory · Mathematics 2025-05-21 Wendy Lowen , Arne Mertens

We construct a functor from the category of graphs to the category of groups which is faithful and "almost" full, in the sense that it induces bijections of the Hom sets up to trivial homomorphisms and conjugation in the category of groups.…

Group Theory · Mathematics 2010-05-19 Adam J. Przezdziecki

While chain complexes are equipped with a differential $d$ satisfying $d^2 = 0$, their generalizations called $N$-complexes have a differential $d$ satisfying $d^N = 0$. In this paper we show that the lax nerve of the category of chain…

Category Theory · Mathematics 2014-04-03 Djalal Mirmohades

In this paper we prove that various quasi-categories whose objects are $\infty$-categories in a very general sense are complete: admitting limits indexed by all simplicial sets. This result and others of a similar flavor follow from a…

Category Theory · Mathematics 2019-10-04 Emily Riehl , Dominic Verity

It is known that strict omega-categories are equivalent through the nerve functor to complicial sets and to sets with complicial identities. It follows that complicial sets are equivalent to sets with complicial identities. We discuss these…

Category Theory · Mathematics 2013-09-03 Richard Steiner

There are infinitely many variants of the notion of Kan fibration that, together with suitable choices of cofibrations and the usual notion of weak equivalence of simplicial sets, satisfy Quillen's axioms for a homotopy model category. The…

Category Theory · Mathematics 2008-10-29 Tibor Beke

In this work, we introduce a 2-categorical variant of Lurie's relative nerve functor. We prove that it defines a right Quillen equivalence which, upon passage to $\infty$-categorical localizations, corresponds to Lurie's scaled…

Algebraic Topology · Mathematics 2020-12-16 Fernando Abellán García , Tobias Dyckerhoff , Walker H. Stern

For a topological space that is homeomorphic to a finite simplicial complex, we prove that the Bartels--Nikolaus assembly functor has a fully faithful right adjoint. Using this, we define for each such topological space $X$ a {\em Whitehead…

Algebraic Topology · Mathematics 2026-04-22 Oscar Harr

In this paper, we compare several functors which take simplicial categories or model categories to complete Segal spaces, which are particularly nice simplicial spaces which, like simplicial categories, can be considered to be models for…

Algebraic Topology · Mathematics 2007-10-11 Julia E. Bergner

We prove that the free algebra functor associated to a symmetric, pseudo commutative 2-monad, from the underlying symmetric monoidal 2-category to the 2-category of algebras and pseudo maps over the 2-monad can be enhanced to a…

Category Theory · Mathematics 2025-09-19 Diego Manco
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