English

Comparing lax functors of $(\infty,2)$-categories

Category Theory 2023-11-22 v1 Algebraic Topology

Abstract

In this work, we study oplax normalised functors of (,2)(\infty,2)-categories. Our main theorem is a comparison between the notion of oplax normalised functor of scaled simplicial sets due to Gagna-Harpaz-Lanari and the corresponding notion in the setting of complete Segal objects in (,1)(\infty,1)-categories studied by Gaitsgory and Rozenblyum. As a corollary, we derive that the Gray tensor product of (,2)(\infty,2)-categories as defined by Gaitsgory-Rozenblyum is equivalent to that of Gagna-Harpaz-Lanari. Moreover, we construct an (,2)(\infty,2)-categorical variant of the quintet functor of Ehresmann, from the (,2)(\infty,2)-category of (,2)(\infty,2)-categories to the (,2)(\infty,2)-category of double (,1)(\infty,1)-categories and show that it is fully faithful. As a key technical ingredient, given (C,E)(\mathbb{C},E) an (,2)(\infty,2)-category equipped with a collection of morphisms and a functor of (,2)(\infty,2)-categories f:CDf:\mathbb{C}\to \mathbb{D}, we construct a right adjoint to the restriction functor ff^* from the (,2)(\infty,2)-category of functors DC ⁣at(,2)\mathbb{D} \to \mathbb{C}\!\operatorname{at}_{(\infty,2)} and natural transformations to the (,2)(\infty,2)-category of functors CC ⁣at(,2)\mathbb{C} \to \mathbb{C}\!\operatorname{at}_{(\infty,2)} and partially lax (according to EE) natural transformations. We apply this new technology of partially lax Kan extensions to the study of complete Segal objects in (,1)(\infty,1)-categories and double (,1)(\infty,1)-categories which allows us to define the notion of an enhanced Segal object (resp. enhanced double (,1)(\infty,1)-category), the former yielding yet another model for the theory of (,2)(\infty,2)-categories.

Cite

@article{arxiv.2311.12746,
  title  = {Comparing lax functors of $(\infty,2)$-categories},
  author = {Fernando Abellán},
  journal= {arXiv preprint arXiv:2311.12746},
  year   = {2023}
}

Comments

104 pages. Comments welcome!

R2 v1 2026-06-28T13:27:36.855Z