Timeline for Finiteness properties for graph of groups decompositions
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 3, 2015 at 8:38 | vote | accept | DavidHume | ||
| Feb 27, 2015 at 18:55 | comment | added | YCor | In my example I assumed the vertex stabilizers to be finitely generated, indeed otherwise there are even easier examples. | |
| Feb 27, 2015 at 17:40 | comment | added | Seirios | A silly example: Take $F= \langle a_1,a_2,\ldots \mid \ \rangle$ a free group of infinite rank, and $f : a_i \mapsto a_{i+1}$ be an isomorphism between the subgroups $\langle a_1,a_2, \ldots \rangle$ and $\langle a_2,a_3, \ldots \rangle$. Then, the associated HNN extension is just $$ \langle t, a_1,a_2, \ldots, \mid ta_1t^{-1}=a_2, ta_2t^{-1} =a_3,\ldots \rangle \simeq \langle t \mid \ \rangle \simeq \mathbb{Z}.$$ | |
| Feb 27, 2015 at 15:34 | answer | added | YCor | timeline score: 4 | |
| Feb 27, 2015 at 13:02 | history | asked | DavidHume | CC BY-SA 3.0 |