Timeline for Surjective maps given by words, redux
Current License: CC BY-SA 2.5
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 9, 2009 at 16:26 | vote | accept | CommunityBot | ||
| Nov 9, 2009 at 16:26 | history | bounty ended | H A Helfgott | ||
| Nov 4, 2009 at 22:16 | comment | added | Greg Kuperberg | Since all of the sets in sight are constructible, you don't have to check "every" z, just a generic z. This may be useful for a computer calculation, if for instance you are happy with non-rigorous evidence that some w is a counterexample. It is not all that useful theoretically. | |
| Nov 4, 2009 at 10:07 | comment | added | H A Helfgott | Thanks for your comment. Yes, as I said in my comment to my own question, I am aware that it is enough for the derivative to be non-singular at any z for the map to be Zariski dense; this would seem to suggest that we have to check that the derivative is singular at every z to be sure that the map is not Zariski dense. (Or is there another way to check this?) I'll be happy to replace "surjective" by "Zariski-dense" - I had either in mind, and both are equally good for my application. I suppose I am thinking of a characteristic considerably greater than the length of the word (or char 0). | |
| Nov 4, 2009 at 0:01 | history | edited | Greg Kuperberg | CC BY-SA 2.5 |
added 1005 characters in body
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| Nov 3, 2009 at 19:49 | history | answered | Greg Kuperberg | CC BY-SA 2.5 |