Enriched quasi-categories and the templicial homotopy coherent nerve
Wendy Lowen, Arne Mertens
TL;DR
This work develops a foundations-level framework for enriched $(\infty,1)$-categories in a general monoidal setting by introducing templicial objects and the templicial nerve, enabling weak enrichment to be realized inside the simplicial objects of $\mathcal{V}$. The authors construct a templicial analogue of the homotopy coherent nerve, prove a central result that locally Kan underlying data yields quasi-categories in $\mathcal{V}$, and establish a rich necklace-categorical apparatus that underpins these constructions. They show that the templicial nerve embeds strictly, relate the templicial and classical nerves, and provide a simplification of categorification via flagged necklace data. The framework recovers the classical quasi-category theory when $\mathcal{V}=\mathrm{Set}$, while offering a natural path toward enriched $\infty$-categories and potential model-categorical equivalences in the non-cartesian setting. Overall, the paper lays the structural groundwork for quasi-categories in a monoidal category and sets the stage for future homotopy-theoretic developments and rectification results.
Abstract
We lay the foundations for a theory of quasi-categories in a monoidal category $\mathcal{V}$ replacing $\mathrm{Set}$, aimed at realising weak enrichment in the category $S\mathcal{V}$ of simplicial objects in $\mathcal{V}$. To accomodate non-cartesian monoidal products, we make use of an ambient category $S_{\otimes}\mathcal{V}$ of templicial - or 'tensor-simplicial' - objects in $\mathcal{V}$, which are certain colax monoidal functors following Leinster. Inspired by the description of the categorification functor due to Dugger and Spivak, we construct a templicial analogue of the homotopy coherent nerve functor which goes from $S\mathcal{V}$-enriched categories to templicial objects. We show that an $S\mathcal{V}$-enriched category whose underlying simplicial category is locally Kan, is turned into a quasi-category in $\mathcal{V}$ by this nerve functor.
