Wiki. “de Rham 叠” [deRham叠]

由概形 $X$ 可构造 $$ X_{\text{dR}}\colon \mathsf {Sch}^{\text{op}} \to \mathsf {Sets}, $$ 满足 $$ X_{\text{dR}}(S):=\operatorname{Hom}(S_{\text{red}},X), \quad \mathcal O_{S_{\text{red}}} = \mathcal O_S / \text{nilpotent}, $$ $$ \mathsf {QCoh}(X_{\text{dR}})\simeq D\mathsf {-Mod}(X). $$