Timeline for Fundamental groups of surfaces
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 19, 2011 at 6:35 | comment | added | HJRW | Igor - I suppose I really had the finitely generated case in mind. | |
| Jun 19, 2011 at 0:39 | comment | added | Igor Rivin | @HW: your statement is actually a nontrivial theorem of Whitehead, so you might be overestimating the OP's mathematical prowess. | |
| Jun 18, 2011 at 10:38 | comment | added | HJRW | unknown - consider the corresponding covering space, and convince yourself that it deformation retracts onto a graph. | |
| Jun 18, 2011 at 10:11 | comment | added | user6976 | It is well known: A. Hoare, A. Karrass and D. Solitar, Subgroups of infinite index in Fuchsiangroups, Math. Z. , 125, 1972, 59–69 | |
| Jun 18, 2011 at 9:57 | comment | added | unkown | how do you prove thay every subgroup of infinite index is free ? | |
| Jun 18, 2011 at 9:51 | history | answered | user6976 | CC BY-SA 3.0 |