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Timeline for Gluing two diffeomorphisms together

Current License: CC BY-SA 2.5

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Apr 1 at 17:37 history edited Piotr Hajlasz
edited tags
Mar 27 at 21:22 answer added Piotr Hajlasz timeline score: 4
Jan 29, 2023 at 18:47 comment added Piotr Hajlasz Did you get a satisfactory answer to your question? I have been struggling with exactly the same problem that you asked. I asked a question mathoverflow.net/q/439635/121665 which when you think about it is more or less a reformulation of your problem: when you have a smooth diffeomorphism of a sphere it is almost linear at infinity when you take a stereographic projection. I stated it in the way I did because of connection to well known problems in topology.
Sep 16, 2010 at 3:08 vote accept Vaughn Climenhaga
Sep 12, 2010 at 22:15 comment added Vaughn Climenhaga @Mariano and @Tom: Ah, right... duly noted. Thanks for pointing that out -- I've edited the question accordingly. (I realise that by doing so I've removed some of the context for your comments, so I'm not sure if this is best practice or not. If it's not, I'm happy to undo the edits and let the comments tell the story.)
Sep 12, 2010 at 22:13 history edited Vaughn Climenhaga CC BY-SA 2.5
Changed question slightly in light of comments
Sep 12, 2010 at 19:01 answer added Bill Thurston timeline score: 12
Sep 12, 2010 at 19:01 comment added Tom Goodwillie You can even make examples such that $f$ has no continuous extension to the closed ball. So maybe revise the question: Either assume that $f$ is given on a closed ball, or else leave the hypothesis alone but only demand that $F$ should agree with $f$ on a smaller ball, not on the whole domain.
Sep 12, 2010 at 18:42 comment added Mariano Suárez-Álvarez (For example: there is a diffeo mapping the unit disc $D$ in $\mathbb R^2$ to the unit disc minus one of its radii.
Sep 12, 2010 at 18:38 comment added Mariano Suárez-Álvarez By "folding" $B(\delta)$ you can construct $f$ satisfying your conditions for which no continuous extension to $\overline{B(\delta)}$ is injective.
Sep 12, 2010 at 18:36 comment added Vaughn Climenhaga I've added a more to-the-point statement of what I'm after -- hopefully that clears it up a bit.
Sep 12, 2010 at 18:36 history edited Vaughn Climenhaga CC BY-SA 2.5
Clarified question
Sep 12, 2010 at 18:30 comment added Mariano Suárez-Álvarez What is exactly your question?
Sep 12, 2010 at 18:15 history asked Vaughn Climenhaga CC BY-SA 2.5