Timeline for Isotopic diffeomorphisms of the sphere
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Jan 27 at 0:25 | comment | added | Ryan Budney | @AllenHatcher thanks, I was drifting to the general pseudoisotopy vs. isotopy question for surfaces. I suppose I should have added, I believe it goes back to Dehn in dimension 2 that homotopy implies isotopy for orientable surfaces. | |
| Jan 26 at 22:38 | comment | added | Allen Hatcher | In dimension 2 the result is older than the Earle-Eells paper which was published in 1969 and which focuses on surfaces of higher genus. There is a paper by Smale in the 1959 AMS Proceedings that proves the stronger result that Diff$(S^2)$ deformation retracts onto $O(2)$. For the $\pi_0$ statement Smale cites an announcement by Munkres in the 1958 AMS Notices. | |
| Jan 20 at 14:54 | history | edited | Timothy Chow | CC BY-SA 4.0 |
Improved formatting, added link
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| Jan 19 at 22:24 | vote | accept | Piotr Hajlasz | ||
| Jan 19 at 22:22 | history | answered | Ryan Budney | CC BY-SA 4.0 |