Quillen equivalences between the model categories of smooth spaces, simplicial sets, and arc-gengerated spaces

Abstract

In the preceding paper, we have constructed a compactly generated model structure on the category $\dcal$ of diffeological spaces together with the adjoint pairs $|\ |_\dcal : \scal \rightleftarrows \dcal : S^\dcal$ and $\tilde{\cdot} : \dcal \rightleftarrows \ccal^0 : R$, where $\scal$ and $\ccal^0$ denote the category of simplicial sets and that of arc-generated spaces, respectively. In this paper, we show that $(|\ |_\dcal, S^\dcal)$ and $(\tilde{\cdot}, R)$ are pairs of Quillen equivalences. Since our approach developed in the preceding paper applies to the category $\ccal h$ of Chen spaces as well, $\ccal h$ is also a compactly generated model category. We also show that the adjoint pair $\mathfrak{S}_\mathfrak{o} : \ccal h \rightleftarrows \dcal : \mathfrak{Ch}^\sharp$ introduced by Stacey is a pair of Quillen equivalences.