Timeline for Short exact sequences every mathematician should know
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 27, 2020 at 9:58 | comment | added | Pedro | (I think there was a nice thread here about how carrying gives a cocycle, too...) | |
| Aug 27, 2020 at 9:58 | comment | added | Pedro | @VivekShende Sounds a bit dramatic but OK. :) | |
| Aug 27, 2020 at 7:39 | comment | added | Vivek Shende | In fact every first grader has to know this short exact sequence: it is how you do addition by “carrying”. | |
| Jun 22, 2020 at 4:20 | comment | added | Arun Debray | In addition to the Bockstein, this is the key example to see that $\mathrm{Ext}(\mathbb Z/p, \mathbb Z/p)\ne 0$, which is nice to know. I also like $0\to\mathbb Z\to\mathbb Z\to\mathbb Z/n\to 0$, as a good first example of a non-split short exact sequence but also just a general insight into how abelian groups behave differently than vector spaces. | |
| S Jun 22, 2020 at 4:04 | history | answered | Pedro | CC BY-SA 4.0 | |
| S Jun 22, 2020 at 4:04 | history | made wiki | Post Made Community Wiki by Pedro |