Timeline for Is the following a sufficient condition for flatness?
Current License: CC BY-SA 2.5
4 events
| when toggle format | what | by | license | comment | |
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| Jun 20, 2010 at 6:07 | answer | added | Angelo | timeline score: 5 | |
| Jun 20, 2010 at 1:53 | comment | added | BCnrd | Kaddar, just to clarify, does "torsion-free" mean each stalk has positive depth, or the (seemingly stronger, if I'm not mistaken) condition that there is a dense Zariski-open $j:U \rightarrow S$ on which $G$ is a vector bundle s.t. $G \rightarrow j_{\ast}j^{\ast}(G)$ has trivial kernel (or equiv., $G$ is subsheaf of $j_{\ast}(E)$ for such a $U$ and some vector bundle $E$ on $U$)? Also, do you insist on the hypothesis only for $G$ given over all of $S$, or are you willing to make the hypothesis over all opens of $S$ too (as otherwise hard to localize the problem)? | |
| Jun 19, 2010 at 19:21 | history | edited | S. Carnahan♦ | CC BY-SA 2.5 |
changed wording
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| Jun 19, 2010 at 16:58 | history | asked | kaddar | CC BY-SA 2.5 |