ScalingStacks

[05TX]

Proposition 3.2. The nerve of [n][n] is Δ⁡[n]\Delta[n]. For categories CC and DD there are natural isomorphisms

nerve⁡(C×D)≈nerve⁡C×nerve⁡Dandnerve⁡(DC)≈nerve⁡(D)nerve⁡(C).\nerve(C\times D)\approx\nerve C\times\nerve D\qquad\text{and}\qquad\nerve(D^{C})\approx\nerve(D)^{\nerve(C)}.

The functor nerve:𝒞​at→𝒮\nerve\colon{\operatorname{\mathcal{C}at}}\rightarrow{\operatorname{\mathcal{S}}} is a full embedding of categories. Furthermore, if CC is a groupoid then nerve⁡(C)\nerve(C) is a Kan complex.

Original mathematics by the credited authors. Source collection and HTML conversion remain in progress.

Charles Rezk

Original source: arXiv:math/9811037v3

Original source page 7

Original source · math/9811037v3