Timeline for Identifying group extension from cohomology class of $D_8$
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
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| Feb 26, 2023 at 7:25 | vote | accept | Igor Sikora | ||
| Feb 23, 2023 at 17:27 | history | edited | Igor Sikora | CC BY-SA 4.0 |
edited body
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| Feb 23, 2023 at 17:08 | comment | added | Igor Sikora | @DerekHolt Thank you, that's fair point. Edited. | |
| Feb 23, 2023 at 17:07 | history | edited | Igor Sikora | CC BY-SA 4.0 |
added 60 characters in body
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| Feb 23, 2023 at 17:04 | answer | added | Nicholas Kuhn | timeline score: 6 | |
| Feb 23, 2023 at 16:07 | comment | added | Derek Holt | Could I just point out that there are two conventions for notation for the dihedral group, and you have not said which one you are using. $D_n$ can denote the dihedral group of order $n$ or of order$2n$. | |
| Feb 23, 2023 at 14:52 | comment | added | Igor Sikora | However, I'm still interested in the question about $D_8$. I suppose that the extensions are already well-studied, so if I can avoid computing cocycles by hand and look into some references, that would be great :) | |
| Feb 23, 2023 at 14:50 | comment | added | Igor Sikora | @BenjaminSteinberg I see, I firstly posted, then looked through the internet (not the best behaviour). Here is the method: ncatlab.org/nlab/show/… | |
| Feb 23, 2023 at 14:49 | history | undeleted | Igor Sikora | ||
| Feb 23, 2023 at 14:49 | history | deleted | Igor Sikora | via Vote | |
| Feb 23, 2023 at 14:49 | comment | added | Benjamin Steinberg | For your second question I suppose it depends how the class is given. If you have an explicit 2-cocycle then the extension is easy to write down. In your example I suppose you need explicit cocycles for each of the generators | |
| Feb 23, 2023 at 14:45 | history | asked | Igor Sikora | CC BY-SA 4.0 |