Timeline for mapping class group of a surface
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 17, 2013 at 4:27 | comment | added | Sam Nead | It seems this question is a duplicate. See the following -- mathoverflow.net/questions/30588/… | |
| Sep 17, 2013 at 4:11 | vote | accept | nikita | ||
| Sep 17, 2013 at 4:10 | vote | accept | nikita | ||
| Sep 17, 2013 at 4:11 | |||||
| Sep 17, 2013 at 4:05 | answer | added | Sam Nead | timeline score: 6 | |
| Sep 17, 2013 at 3:22 | comment | added | nikita | for example, how do you calculate it for these family diffeomorphisms: take an axis (resp. a plane) such that the surface is symmetric about that, rotate the points by 180 degrees (resp. reflect) about the axis (resp. plane). | |
| Sep 17, 2013 at 3:21 | comment | added | Ryan Budney | If your surface diffeomorphism is given as a product of Dehn twists, the empty procedure works. The Lickorish proof is given in terms of the action of the mapping class group on the collection of closed curves in the surface (and the homology of the surface). | |
| Sep 17, 2013 at 3:15 | comment | added | Andy Putman | As Misha said, the usual proof that the mapping class group is generated by Dehn twists (as presented in many sources, including Farb-Margalit's primer) is constructive in a straightforward way. This question is too vague to admit of an answer beyond that. How is your diffeomorphism presented to you? | |
| Sep 17, 2013 at 3:06 | comment | added | Misha | Did you read the Lickorish proof that mcg is generated by Dehn twists? It is very constructive. | |
| Sep 17, 2013 at 2:58 | history | asked | nikita | CC BY-SA 3.0 |