Timeline for Irreducible components of an algebraic stack
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 19, 2021 at 17:03 | comment | added | Dan Petersen | You and me both! | |
| May 19, 2021 at 12:50 | comment | added | Tommaso Scognamiglio | Really thank you! Sorry with stacks I'm never sure if I'm missing something.. | |
| May 18, 2021 at 17:45 | comment | added | Dan Petersen | @Tommaso One can reason as follows: smooth morphisms are open, so if $V \subset W$ is an open subset then so is $p(V) \subset X$. | |
| May 18, 2021 at 9:09 | comment | added | Tommaso Scognamiglio | If you call $R=W\times_{\mathcal{X}}W$ the open substacks of $X$ shouldn't be given by the $R$ invariant open subschemes of $W$? How you pick $V$ to be $R$ invariant in general? (I'm probably missing something basic, sorry! I'm really new to the stacky language) | |
| May 18, 2021 at 8:58 | comment | added | Dan Petersen | @Tommaso Choose $p:W \to X$ a smooth surjection from a scheme, and let $V \subset W$ be open dense smooth. Then $p(V)$ is an open dense smooth substack of $X$. | |
| May 18, 2021 at 6:06 | comment | added | Tommaso Scognamiglio | For general stacks,how can you choose such an open dense substack? | |
| May 17, 2021 at 6:24 | vote | accept | Tommaso Scognamiglio | ||
| May 17, 2021 at 3:42 | history | answered | Dan Petersen | CC BY-SA 4.0 |