Timeline for Sheafification - Why does twice suffice?
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
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| Apr 13, 2017 at 12:58 | history | edited | CommunityBot |
replaced http://mathoverflow.net/ with https://mathoverflow.net/
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| May 1, 2012 at 21:37 | answer | added | Tom Leinster | timeline score: 21 | |
| May 1, 2012 at 10:36 | answer | added | Buschi Sergio | timeline score: 1 | |
| Apr 30, 2012 at 21:01 | vote | accept | Dedalus | ||
| Apr 30, 2012 at 19:29 | comment | added | Sergio A. Yuhjtman | It is possible to construct the associated sheaf functor in only one step. This is due to Eduardo Dubuc. The key idea is to consider "locally compatible families" instead of "compatible families". You can read the details here: cms.dm.uba.ar/academico/carreras/licenciatura/tesis/… (spanish, sorry) Page 19, (3.2). | |
| Apr 30, 2012 at 18:18 | answer | added | Simon Markett | timeline score: 11 | |
| Apr 30, 2012 at 18:18 | history | edited | Martin Brandenburg |
edited tags
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| Apr 30, 2012 at 18:17 | comment | added | Martin Brandenburg | Related interesting MO questions: mathoverflow.net/questions/90969 , mathoverflow.net/questions/54128 | |
| Apr 30, 2012 at 16:03 | comment | added | Mike Shulman | The problem is exactly that: in $X^+$ there may be families that become compatible, hence ought to have gluings, but were not compatible in $X$, so that we did not already add gluings for them. By definition of $X^+$, this happens precisely when their restrictions to overlaps agree upon further passage to a cover, which in turn can happen precisely when $X$ is not separated. So I think the theorem that $X^+$ is a sheaf when $X$ is separated is a "generalization of this notion to become rigorous". | |
| Apr 30, 2012 at 15:28 | comment | added | Tom Goodwillie | I suggest that you should look at the other answers besides Sherry's at that other question. | |
| Apr 30, 2012 at 14:49 | history | asked | Dedalus | CC BY-SA 3.0 |