Timeline for central extensions of Diff(S^1) and of the semigroup of annuli
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 14, 2011 at 11:34 | comment | added | Dylan Thurston | @André: Thanks! I think I've been confused about this for years. | |
| Apr 14, 2011 at 10:23 | comment | added | André Henriques | The center of the the universal central extension of $\mathrm{Diff}(S^1)$ is $\mathbb Z\times\mathbb R$ (the $\mathbb Z$ has to do with "minimal energy", while the $\mathbb R$ has to do with "central charge"). So your answer is orthogonal to my question. | |
| Apr 14, 2011 at 9:04 | comment | added | Dylan Thurston | I spent some time trying to find an explicit map to the $\mathbb{R}$ extension, without luck so far. It's a bit mysterious. | |
| Apr 14, 2011 at 0:27 | history | edited | Dylan Thurston | CC BY-SA 3.0 |
corrected R vs Z central extension
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| Apr 13, 2011 at 23:28 | history | answered | Dylan Thurston | CC BY-SA 3.0 |