English

$\mathrm{LMod}_{R}(\mathcal{V})$-enriched $\infty$-categories are left $R$-module objects of $\mathcal{C}at^{\mathcal{V}}$ and $\mathcal{C}at^{\mathcal{V}}$-enriched $\infty$-functors

Category Theory 2025-02-25 v3

Abstract

We investigate LModR(V)\mathrm{LMod}_{R}(\mathcal{V})-enriched \infty-categories, where RR is an E2\mathbb{E}_2-ring in a presentable E2\mathbb{E}_2-monoidal \infty-category V\mathcal{V}, using V\mathcal{V}-enriched \infty-category theory. We prove the equivalence of CatLModR(V)\mathcal{C}at_{\infty}^{\mathrm{LMod}_{R}(\mathcal{V})} (the \infty-category of LModR(V)\mathrm{LMod}_{R}(\mathcal{V})-enriched \infty-categories) and LModR(CatV)\mathrm{LMod}_{R}(\mathcal{C}at_{\infty}^{\mathcal{V}}) (left RR-modules in CatV\mathcal{C}at_{\infty}^{\mathcal{V}}). For RR an E2\mathbb{E}_2-ring in a presentable E3\mathbb{E}_3-monoidal \infty-category, they are also equivalent to FunCatV(B2R,CatV)Fun^{\mathcal{C}at_{\infty}^{\mathcal{V}}}(B^2R,\mathcal{C}at_{\infty}^{\mathcal{V}}), where B2()B^2(-) is the "22-delooping". This result generalizes: if RR is an En+1\mathbb{E}_{n+1}-ring in a presentable En+1\mathbb{E}_{n+1}-monoidal \infty-category, (,n)(\infty,n)-categories enriched in LModR(V)\mathrm{LMod}_{R}(\mathcal{V}) are equivalent to BnRB^nR-modules in V\mathcal{V}-enriched (,n)(\infty,n)-categories, where Bn()B^n(-) is the "nn-delooping". A notable case is V=Sp\mathcal{V} = \mathcal{S}p and R=HkR = \mathbb{H}\mathrm{k}, the Eilenberg-MacLane spectrum of a commutative ring kk. In this case, the results provide two new descriptions of D(k)\mathcal{D}(k) the \infty-category of dg-categories over kk, a key object in derived algebraic geometry.

Keywords

Cite

@article{arxiv.2406.15884,
  title  = {$\mathrm{LMod}_{R}(\mathcal{V})$-enriched $\infty$-categories are left $R$-module objects of $\mathcal{C}at^{\mathcal{V}}$ and $\mathcal{C}at^{\mathcal{V}}$-enriched $\infty$-functors},
  author = {Matteo Doni},
  journal= {arXiv preprint arXiv:2406.15884},
  year   = {2025}
}

Comments

In Theorem 6.1, R must be E2 instead of E1. The above error also affects Corollary 6.3, making it incorrect as well

R2 v1 2026-06-28T17:15:57.075Z