Timeline for Acyclic aspherical spaces with acyclic fundamental groups
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 28, 2017 at 21:45 | vote | accept | John Klein | ||
| Nov 28, 2017 at 21:42 | comment | added | Anton Fetisov | @JeffStrom Take a look at the Wiki page on perfect groups. In particular, $A_5$ and the groups of elementary infinite matrices over a ring $E(R)$ are both perfect and non-acyclic. For $E(R)$ its $H^2(\mathbb Z)$ is equal to $K_2(R)$. | |
| Nov 28, 2017 at 21:38 | comment | added | John Klein | I think so, take the binary icosahedral group. | |
| Nov 28, 2017 at 21:20 | vote | accept | John Klein | ||
| Nov 28, 2017 at 21:39 | |||||
| Nov 28, 2017 at 21:09 | answer | added | Johannes Ebert | timeline score: 17 | |
| Nov 28, 2017 at 20:05 | comment | added | Jeff Strom | What is the distinction between $\pi$ being acyclic and being perfect? I mean, I see the logical distinction; but are there examples to show that they are actually different concepts? | |
| Nov 28, 2017 at 18:55 | history | asked | John Klein | CC BY-SA 3.0 |