Timeline for Group extensions and actions on categories
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 6, 2016 at 0:06 | comment | added | Qiaochu Yuan | The equivalence between autoequivalences and bitorsors is a version of the Eilenberg-Watts theorem; it can be deduced from the universal property of the Yoneda embedding. | |
| Feb 24, 2012 at 2:16 | comment | added | Evan Jenkins | @Erwan: I doubt it's in SGA7, but the argument should be almost exactly the same. @David: In Grothendieck's article, he works in an arbitrary (Grothendieck) topos, so I think the answer to your question is yes (modulo checking what Grothendieck actually says, as opposed to my rough translation of it). | |
| Feb 18, 2012 at 14:54 | comment | added | David Carchedi | Does this work also for $G$ and $H$ which are topological or Lie by using classifying their classifying topoi? | |
| Feb 15, 2012 at 1:40 | comment | added | Erwan Biland | By the way, if $A$ is an algebra, there is a similar statement for strongly $G$-graded algebras with unit component $A$, and actions of $G$ on the category of $A$-modules. Do you know if this is also done in SGA 7 ? Thanks again. | |
| Feb 15, 2012 at 1:19 | vote | accept | Erwan Biland | ||
| Feb 14, 2012 at 21:32 | history | answered | Evan Jenkins | CC BY-SA 3.0 |