English
Related papers

Related papers: On Hofmann-Streicher universes

200 papers

We use the terms $\infty$-categories and $\infty$-functors to mean the objects and morphisms in an $\infty$-cosmos: a simplicially enriched category satisfying a few axioms, reminiscent of an enriched category of fibrant objects.…

Category Theory · Mathematics 2016-06-14 Emily Riehl , Dominic Verity

We define a natural 2-categorical structure on the base category of a large class of Grothendieck fibrations. Given any model category $\mathbf{C}$, we apply this construction to a fibration whose fibers are the homotopy categories of the…

Category Theory · Mathematics 2022-02-24 Joseph Helfer

Presheaves on a small category are well-known to correspond via a category of elements construction to ordinary discrete fibrations over that same small category. Work of R. Par\'e proposes that presheaves on a small double category are…

Category Theory · Mathematics 2021-01-19 Michael Lambert

The unstraightening construction due to Lurie establishes an equivalence between presheaves and fibrations, using one prominent model of $(\infty,1)$-categories, namely quasi-categories. In this work we generalize this result by proving…

Category Theory · Mathematics 2025-06-06 Nima Rasekh

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

These are expanded lecture notes from lectures given at the Workshop on higher structures at MATRIX Melbourne. These notes give an introduction to Feynman categories and their applications. Feynman categories give a universal categorical…

Algebraic Topology · Mathematics 2017-06-02 Ralph M. Kaufmann

Let $Ham (M,\omega ) $ denote the Frechet Lie group of Hamiltonian symplectomorphisms of a monotone symplectic manifold $(M, \omega) $. Let $NFuk (M, \omega)$ be the $A _{\infty} $-nerve of the Fukaya category $Fuk (M, \omega)$, and let…

Symplectic Geometry · Mathematics 2023-01-20 Yasha Savelyev

In this paper, we analyze and compare three of the many algebraic structures that have been used for modeling dependent type theories: categories with families, split type-categories, and representable maps of presheaves. We study these in…

Logic · Mathematics 2023-06-22 Benedikt Ahrens , Peter LeFanu Lumsdaine , Vladimir Voevodsky

We show that the homotopy theory of strict 2-categories embeds in that of $(\infty,2)$-categories in the form of 2-precomplicial sets. More precisely, we construct a nerve-categorification adjunction that is a Quillen pair between Lack's…

Algebraic Topology · Mathematics 2019-02-15 Viktoriya Ozornova , Martina Rovelli

A category of FI type is one which is sufficiently similar to finite sets and injections so as to admit nice representation stability results. Several common examples admit a Grothendieck fibration to finite sets and injections. We begin by…

Representation Theory · Mathematics 2023-01-27 Joe Moeller

We study the properties of the constructible universe, L, over intuitionistic theories. We give an extended set of fundamental operations which is sufficient to generate the universe over Intuitionistic Kripke-Platek set theory without…

Logic · Mathematics 2023-09-27 Richard Matthews , Michael Rathjen

We show how to treat families of $\infty$-categories fibered in categorical patterns (e.g., $\infty$-operads and monoidal $\infty$-categories) in terms of fibrations by relativizing the Grothendieck construction. As applications, we…

Category Theory · Mathematics 2024-04-02 Kensuke Arakawa

Given a finite cocommutative Hopf algebra $A$ over a commutative regular ring $R$, the lattice of localising tensor ideals of the stable category of Gorenstein projective $A$-modules is described in terms of the corresponding lattices for…

Representation Theory · Mathematics 2022-06-14 Dave Benson , Srikanth B. Iyengar , Henning Krause , Julia Pevtsova

Motivated by ideas from string theory and quantum field theory new invariants of knots and 3-dimensional manifolds have been constructed from complex algebraic structures such as Hopf algebras (Reshetikhin and Turaev), monoidal categories…

Geometric Topology · Mathematics 2007-05-23 Ulrike Tillmann

We set up a fibred categorical theory of obstruction and classification of morphisms that specializes to the one of monoidal functors between categorical groups and also to the Schreier-Mac Lane theory of group extensions. Further…

Category Theory · Mathematics 2021-04-14 Alan S. Cigoli , Sandra Mantovani , Giuseppe Metere , Enrico M. Vitale

Most categorical models for dependent types have traditionally been heavily set based: contexts form a category, and for each we have a set of types in said context -- and for each type a set of terms of said type. This is the case for…

Logic in Computer Science · Computer Science 2023-12-25 Greta Coraglia , Jacopo Emmenegger

We develop a homotopical framework for small categories that extends classical invarints of algebraic topology to the categorical setting. Our approach is based on the construction of genuine path category, obtained trough a localization…

Category Theory · Mathematics 2026-05-19 Isaac Carcacía-Campos , Enrique Macías-Virgós , David Mosquera-Lois

Let $G$ be a finite group and $N\unlhd G$. In this note, we construct a class poset of $G$ for some cyclic subgroup $C$ of $G$. And we find a relation between $m_{G,N}$ and the Euler characteristic of some nerve spaces of these posets(see…

Group Theory · Mathematics 2018-03-06 Heguo Liu , Xingzhong Xu , Jiping Zhang

This PhD thesis deals with some new models of intensional type theory and the Univalence Axiom introduced by Vladimir Voevodsky. Our work takes place in the framework of the definitions of type-theoretic fibration categories (the notion of…

Category Theory · Mathematics 2016-04-13 Anthony Bordg

This article is a sequel to hep-th/9411050, q-alg/9412017. In Chapter 1 we associate with every Cartan matrix of finite type and a non-zero complex number $\zeta$ an abelian artinian category $\FS$. We call its objects {\em finite…

q-alg · Mathematics 2008-02-03 M. Finkelberg , V. Schechtman