Timeline for Extensions in a full subcategory
Current License: CC BY-SA 4.0
2 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 18, 2021 at 5:27 | comment | added | Aurélien Djament | No, it does not hold. For example, take for C (resp. D) the category of modules over the ring Z (resp. Z/4), where Z is the ring of integers. Ext vanishes from degree 2 in C, but is zero in no positive degree in D. | |
| May 17, 2021 at 16:00 | history | asked | user197402 | CC BY-SA 4.0 |