Timeline for Does a universal Frobenius map exist?
Current License: CC BY-SA 2.5
12 events
| when toggle format | what | by | license | comment | |
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| Dec 15, 2009 at 11:52 | vote | accept | Marc Nieper-Wißkirchen | ||
| Dec 15, 2009 at 11:44 | history | edited | Marc Nieper-Wißkirchen | CC BY-SA 2.5 |
added 8 characters in body
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| Dec 9, 2009 at 9:49 | answer | added | javier | timeline score: 3 | |
| Dec 9, 2009 at 4:41 | history | edited | Pete L. Clark |
added tag (characteristic p)
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| Dec 1, 2009 at 0:36 | answer | added | Mikhail Bondarko | timeline score: 1 | |
| Nov 28, 2009 at 21:17 | comment | added | Marc Nieper-Wißkirchen | Improved my question. | |
| Nov 28, 2009 at 20:41 | history | edited | Marc Nieper-Wißkirchen | CC BY-SA 2.5 |
Clarified question.
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| Nov 26, 2009 at 21:53 | comment | added | Andrew Critch | I suggest editing your question to include one or more precise formulations, and also a discussion like the comment you just wrote; MO users like to see partial progress in question statements, because it both motivates and provides a starting place for others. I'd like to see this question get more upvotes so it attracts attention and gets an answer. | |
| Nov 26, 2009 at 12:19 | comment | added | Marc Nieper-Wißkirchen | Something like this, yes. I have the following picture in mind: In some sense it should be possible to view the category of Z-modules as a sheaf of categories over Spec Z such that the fibre over Spec F_p is just the category of F_p-modules. A natural transformation f of the identity functor on the category of Z-modules should restrict to a natural transformation f_p of the identity functor on the category of F_p-modules. In this naive picture one cannot expect the existence of an f such that f_p is the Frobenius on F_p-modules for all primes p. But is there way to make this picture work? | |
| Nov 26, 2009 at 9:26 | comment | added | Andrew Critch | I may have initially misinterpreted this question. Marc, are you asking if there is some $f_U:U\to U$ such that for any ring $R$ of characteristic $p$, there is a unique morphism $u_R:Spec(R)\to U$ such that the pullback of $f_U$ along $u_R$ is the Frobenius ($p$th power) map $f_R:R\to R$? | |
| Nov 26, 2009 at 2:58 | history | edited | Andrew Critch |
edited tags
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| Nov 25, 2009 at 20:30 | history | asked | Marc Nieper-Wißkirchen | CC BY-SA 2.5 |