nLab
(infinity,0)-category

Following the terminology of (n,r)-categories, an (,0)(\infty,0)-category is an ∞-category in which every jj-morphism (for j>0j \gt 0) is invertible.

So in an (,0)(\infty,0)-category every morphism is invertible. Such ∞-categories are usually called ∞-groupoids.

This is directly analogous to how a 0-category is equivalent to a set, a (1,0)-category is equivalent to a groupoid, and so on. (In general, an (n,0)-category is equivalent to an n-groupoid.)

The term “(,0)(\infty,0)-category” is rarely used, but does for instance serve the purpose of amplifying the generalization from Kan complexes, which are one model for ∞-groupoids, to quasi-categories, which are a model for (∞,1)-categories.

Revised on July 3, 2009 19:02:29 by Toby Bartels (71.104.230.172)