Timeline for Why is the fibered coproduct of affine schemes not affine?
Current License: CC BY-SA 2.5
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 25, 2010 at 6:47 | answer | added | Sasha | timeline score: 6 | |
| Jun 24, 2010 at 9:01 | comment | added | Martin Brandenburg | Just keep in mind in which categories you talk about coequalizers. In the category of affine schemes, well, the coequalizer is of course affine (and it exists). But probably you want to think about the coequalizer of schemes, whose objects happen to be affine. See also mathoverflow.net/questions/9961/colimits-of-schemes and (sorry!) mathoverflow.net/questions/23478/… ;-) | |
| Jun 24, 2010 at 2:26 | comment | added | David E Speyer | I think some of the maps in your opening paragraph are backwards. If you want to discuss coproducts of schemes, then the maps on rings should be $R_1 \to S$ and $R_2 \to S$ . (As in Andreas's example.) There may be some later typos of this sort, I'm not sure. | |
| Jun 24, 2010 at 2:12 | history | edited | Yemon Choi | CC BY-SA 2.5 |
cleaned up English in the title
|
| Jun 24, 2010 at 2:12 | answer | added | Andreas Blass | timeline score: 28 | |
| Jun 24, 2010 at 1:47 | history | asked | Mikhail Gudim | CC BY-SA 2.5 |