The Stacks project

Proposition 77.5.1. Let $S$ be a scheme. Let $f : X \to Y$ be a morphism of algebraic spaces over $S$. Let $\mathcal{F}$ be a quasi-coherent sheaf on $X$. Let $x \in |X|$ with image $y \in |Y|$. Assume that

  1. $f$ is locally of finite presentation,

  2. $\mathcal{F}$ is of finite presentation, and

  3. $\mathcal{F}$ is flat at $x$ over $Y$.

Then there exists a commutative diagram of pointed schemes

\[ \xymatrix{ (X, x) \ar[d] & (X', x') \ar[l]^ g \ar[d] \\ (Y, y) & (Y', y') \ar[l] } \]

whose horizontal arrows are étale such that $X'$, $Y'$ are affine and such that $\Gamma (X', g^*\mathcal{F})$ is a projective $\Gamma (Y', \mathcal{O}_{Y'})$-module.

Proof. As formulated this proposition immediately reduces to the case of schemes, which is More on Flatness, Proposition 38.12.4. $\square$


Comments (0)


Post a comment

Your email address will not be published. Required fields are marked.

In your comment you can use Markdown and LaTeX style mathematics (enclose it like $\pi$). A preview option is available if you wish to see how it works out (just click on the eye in the toolbar).

Unfortunately JavaScript is disabled in your browser, so the comment preview function will not work.

All contributions are licensed under the GNU Free Documentation License.




In order to prevent bots from posting comments, we would like you to prove that you are human. You can do this by filling in the name of the current tag in the following input field. As a reminder, this is tag 0CVY. Beware of the difference between the letter 'O' and the digit '0'.