Timeline for Why is every symplectomorphism of the unit disk Hamiltonian isotopic to the identity?
Current License: CC BY-SA 2.5
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| Dec 20, 2009 at 5:48 | comment | added | Greg Kuperberg | Also I didn't have to be so fancy as to use a weighted geometric mean of the measures. You could also use an arithmetic mean. | |
| Dec 20, 2009 at 0:15 | comment | added | Greg Kuperberg | Two points on your points: (1) What you graciously call my idea is really an elaboration of two general precepts that are not due to me. One is that deformation retracts, or even more generally homotopy equivalences, are very powerful. The other is that Moser's trick is very powerful. (2) There is a symplectic version of Moser's trick, but it indeed does not give you a homotopy equivalence between diffeomorphisms and symplectomorphisms. The volume case is nicer because the set of volume structures is convex and therefore contractible. | |
| Dec 20, 2009 at 0:00 | history | edited | Ilya Grigoriev | CC BY-SA 2.5 |
added 10 characters in body
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| Dec 19, 2009 at 23:55 | history | answered | Ilya Grigoriev | CC BY-SA 2.5 |