Timeline for Does anyone have a good example of an injective resolution?
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
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| Mar 30 at 15:47 | comment | added | tj_ | For a finite dimensional Hopf algebra $H$ over a field, projectives are injective. If $M$ is a finite dimensional $H$-module, you can take a $H$-projective resolution $P\to M^\ast$ of the dual $M^\ast=Hom_H(M,H)$. Then, dualizing yields an $H$-injective resolution $M\to P^\ast$. | |
| Mar 29 at 23:51 | comment | added | Denis T | $\operatorname{Hom}_{\mathbb Z}(-, \mathbb Q / \mathbb Z)$ is a faithfully exact functor which sends flats to projectives. In the case of a noetherian scheme it is basically what's written in the comment above, but works over any ring just as well. | |
| Mar 29 at 23:25 | answer | added | Javier Herrero | timeline score: 6 | |
| Mar 29 at 16:10 | comment | added | Antonius | Products of skyscraper sheaves with injective stalks. | |
| Mar 28 at 19:45 | review | Close votes | |||
| Apr 5 at 3:03 | |||||
| S Mar 28 at 18:19 | review | First questions | |||
| Mar 28 at 23:25 | |||||
| S Mar 28 at 18:19 | history | asked | A. Kriegman | CC BY-SA 4.0 |