Timeline for Are schemes obtained from reduced schemes by gluing infinitesimal stuff along a reduced closed subscheme?
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 21, 2019 at 4:25 | comment | added | Will Sawin | @Qfwfq Re: conormal, yes, of course. For your second question, I would imagine one can find an obstruction in the next level of the filtration or in the extension class. | |
| May 20, 2019 at 20:55 | comment | added | Qfwfq | Thank you for the answer: it's what I was looking for. (By "cotangent bundle" I assume you meant the conormal sheaf $N^*$). A question: does also the reverse implication hold? That is, if $N^*_{Y/X}=N^*_{Y/X_{red}}\oplus N^*_{Y/Z}$ then does the coproduct condition hold? I imagine it doesn't. | |
| May 20, 2019 at 14:29 | vote | accept | Qfwfq | ||
| May 20, 2019 at 2:18 | history | answered | Will Sawin | CC BY-SA 4.0 |