Timeline for Frobenius splitting and derived Cartier isomorphism
Current License: CC BY-SA 2.5
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 15, 2020 at 7:27 | history | edited | CommunityBot |
Commonmark migration
|
|
| Apr 13, 2017 at 12:57 | history | edited | CommunityBot |
replaced http://mathoverflow.net/ with https://mathoverflow.net/
|
|
| Sep 29, 2011 at 1:13 | answer | added | Piotr Achinger | timeline score: 5 | |
| May 31, 2011 at 7:13 | vote | accept | Piotr Achinger | ||
| May 31, 2011 at 2:51 | answer | added | Matt | timeline score: 9 | |
| May 30, 2011 at 11:23 | comment | added | Piotr Achinger | Great! Why don't you post this as an answer? | |
| May 29, 2011 at 19:10 | comment | added | Matt | I believe that even if Frobenius doesn't lift you still get that a Frobenius split variety (with nice assumptions) will lift to $W_2(k)$. This is because even though the obstruction to lifting Frobenius $\eta\in Ext^1(\Omega^1, B^1)$ is non-zero, the obstruction to merely lifting $X$ is the image of $\eta$ under the connecting homomorphism $Ext^1(\Omega^1, B^1)\to Ext^2(\Omega^1, \mathcal{O}_X)$. By the splitting assumption this map is $0$ and hence there is no obstruction to lifting $X$. See V. Srinivas Decomposition of the de Rham Complex. | |
| Mar 21, 2011 at 17:50 | history | edited | Piotr Achinger | CC BY-SA 2.5 |
added 393 characters in body
|
| Mar 21, 2011 at 15:05 | history | asked | Piotr Achinger | CC BY-SA 2.5 |