Timeline for Can relative flatness of a sheaf be tested using (faithfully) flat morphisms?
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 29, 2015 at 10:31 | vote | accept | Bernie | ||
| Sep 28, 2015 at 18:48 | comment | added | Ben Wieland | No, you cannot drop the "faithfully." For example, if $X$ is the empty scheme, it is flat, but it detects nothing. The empty scheme is a good heuristic for testing whether faithfulness is relevant. In fact, given the characterization of faithfully flat morphisms among flat morphisms as the surjective ones (ie, the ones with nonempty fibers), it is the whole story. | |
| Sep 28, 2015 at 16:36 | answer | added | Anton Fonarev | timeline score: 3 | |
| Sep 28, 2015 at 15:12 | history | asked | Bernie | CC BY-SA 3.0 |