The Stacks project

Lemma 85.36.5. Let $S$ be a scheme. Let $X$ be an algebraic space over $S$. Let $U$ be a simplicial algebraic space over $S$. Let $a : U \to X$ be an augmentation. Let $\mathcal{A} \subset \textit{Ab}(U_{\acute{e}tale})$ denote the weak Serre subcategory of cartesian abelian sheaves. If $U$ is a proper hypercovering of $X$, then the functor $a^{-1}$ defines an equivalence

\[ D^+(X_{\acute{e}tale}) \longrightarrow D_\mathcal {A}^+(U_{\acute{e}tale}) \]

with quasi-inverse $Ra_*$. Here $a : \mathop{\mathit{Sh}}\nolimits (U_{\acute{e}tale}) \to \mathop{\mathit{Sh}}\nolimits (X_{\acute{e}tale})$ is as in Section 85.32.

Proof. Observe that $\mathcal{A}$ is a weak Serre subcategory by Lemma 85.12.6. The equivalence is a formal consequence of the results obtained so far. Use Lemmas 85.36.2 and 85.36.3 and Cohomology on Sites, Lemma 21.28.5. $\square$

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