Timeline for Picard scheme of family of quartic surfaces
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 16, 2020 at 9:30 | comment | added | Daniel Loughran | Yes I finally get it now. I think I was getting confused between the small and big fppf site; now it all makes sense, thanks! | |
| Jul 15, 2020 at 10:20 | comment | added | Angelo | There is no such flat map; the special fibers of $Pic_{Q/U} \to U$ are concentrated on proper subvarieties of $U$. | |
| Jul 14, 2020 at 20:32 | comment | added | Daniel Loughran | Thanks this makes sense. Still, I'm struggling to come up with a flat map $V \to U$ with $V$ connected such that $Pic_{Q/U}(V) \neq \mathbb{Z}$, since the genetic quartic surface has Picard group $\mathbb{Z}$. | |
| Jul 14, 2020 at 19:56 | comment | added | Angelo | Formation of the Picard scheme commutes with base change, so the fibers of $Pic_{Q/U} \to U$ are complicated. | |
| Jul 14, 2020 at 19:43 | history | asked | Daniel Loughran | CC BY-SA 4.0 |