Timeline for What is a proper stack?
Current License: CC BY-SA 2.5
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 12, 2020 at 21:52 | answer | added | Pulcinella | timeline score: 1 | |
| Jan 27, 2010 at 9:04 | vote | accept | Andrea Ferretti | ||
| Jan 26, 2010 at 22:26 | answer | added | t3suji | timeline score: 10 | |
| Jan 26, 2010 at 20:03 | comment | added | Emerton | If you look in Deligne--Mumford, you will find the definition, as well as a statement of the valuative criterion. | |
| Jan 26, 2010 at 19:58 | comment | added | Andrea Ferretti | This is exactly what I'm asking. Can you argue a bit more on the standard terminology in an answer? The definition I have seen says that a morphism of stacks has property P iff it is representable and and every morphism between schemes obtained from it by base change has property P. | |
| Jan 26, 2010 at 18:58 | comment | added | t3suji | Why do you say that a proper morphism `as usual it should be representable'? There are proper morphisms that are not representable. For instance, the morphism from the classifying stack of a finite group to a point is proper. This is an example of a complete Deligne-Mumford stack (I also prefer to use 'complete' for spaces and 'proper' for morphisms). | |
| Jan 26, 2010 at 18:11 | history | asked | Andrea Ferretti | CC BY-SA 2.5 |