Timeline for Counting isomorphism classes via extensions
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 6, 2011 at 19:21 | vote | accept | Todd Leason | ||
| Sep 19, 2011 at 22:01 | answer | added | Ralph | timeline score: 8 | |
| Sep 11, 2011 at 22:38 | comment | added | David Roberts♦ | You have to take into account the size of the outer automorphism group of $C$. Given any extension $Q$ acts on $C$ by outer automorphisms, and this action is trivial if and only if $C$ is central. You probably want to look at the series of papers 'Cohomology theory in abstract groups' by Eilenberg and MacLane. | |
| Sep 11, 2011 at 22:35 | history | edited | Todd Leason | CC BY-SA 3.0 |
Added the last sentence.
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| Sep 11, 2011 at 22:23 | history | asked | Todd Leason | CC BY-SA 3.0 |