Timeline for What is your favorite isomorphism?
Current License: CC BY-SA 2.5
3 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 3, 2010 at 1:28 | comment | added | Victor Protsak | I find the parenthetical example contorted, but here is a related one that's important in the theory of formal groups: the multiplicative group of a field, $(x,y)\mapsto xy,$ where $x,y\ne 0,$ is isomorphic to the group with the group law $(x,y)\mapsto x+y+xy,$ where $x,y\ne -1.$ | |
| Sep 2, 2010 at 22:11 | history | edited | Tracy Hall | CC BY-SA 2.5 |
reals -> positive reals
|
| Sep 2, 2010 at 21:39 | history | answered | Tracy Hall | CC BY-SA 2.5 |