Timeline for Limit for divergent sequences
Current License: CC BY-SA 2.5
13 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 18, 2012 at 14:40 | vote | accept | Martin Brandenburg | ||
| May 18, 2012 at 13:48 | answer | added | Ramiro de la Vega | timeline score: 2 | |
| Feb 2, 2010 at 19:24 | comment | added | Gerald Edgar | Perhaps not an ultrafilter. For example the evens and the odds could both have nonzero values. But it is true that such a thing cannot be proved to exist (in ZF). Hahn-Banach should be enough, though, which is strictly weaker than Axiom of Choice. | |
| Feb 2, 2010 at 18:38 | comment | added | Martin Brandenburg | interesting, perhaps. what do you think? | |
| Feb 2, 2010 at 18:23 | comment | added | Qiaochu Yuan | Wouldn't such a homomorphism allow you to construct a non-principal ultrafilter on N? | |
| Feb 2, 2010 at 16:46 | comment | added | Martin Brandenburg | the rules are simple: if you are a logician and can prove that in some formal sense this hom. cannot be written down, feel free indicate a proof. if you can write something down in an informal sense, please let me know. otherwise, nothing has to be said. | |
| Feb 2, 2010 at 16:40 | answer | added | Pete L. Clark | timeline score: 8 | |
| Feb 2, 2010 at 16:07 | comment | added | S. Carnahan♦ | I think a logician can say this better than I can, but the precise meaning of "writing something down" seems to be at the center of your question. Therefore, it is strange to me that you don't want a discussion about mathematical logic here. | |
| Feb 2, 2010 at 15:59 | comment | added | Martin Brandenburg | no this is not imposed | |
| Feb 2, 2010 at 15:51 | comment | added | S. Carnahan♦ | Are you demanding that the homomorphism agree with limits when they exist? In that case, the kernel contains not only finite sequences, but those with infinite support that converge to zero. | |
| Feb 2, 2010 at 15:37 | answer | added | Anton Petrunin | timeline score: 2 | |
| Feb 2, 2010 at 15:24 | history | asked | Martin Brandenburg | CC BY-SA 2.5 |