Timeline for Universal homeomorphism of stacks and etale sites
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 17, 2017 at 2:23 | vote | accept | Jingren Chi | ||
| Aug 15, 2017 at 8:45 | answer | added | David Rydh | timeline score: 5 | |
| Jul 31, 2017 at 18:04 | history | edited | Jingren Chi | CC BY-SA 3.0 |
added 40 characters in body; edited tags
|
| Jul 29, 2017 at 2:03 | history | edited | Jingren Chi | CC BY-SA 3.0 |
deleted 5 characters in body; edited title
|
| Jul 28, 2017 at 20:08 | comment | added | Niels | @HCCH : if $k$ is algebraically closed, the étale topos of $BG$ is $G$-Sets, so it is not equivalent to the étale topos of $spec (k)$, which is Sets. So considering the topoi doesn't help. | |
| Jul 28, 2017 at 19:15 | history | edited | Jingren Chi | CC BY-SA 3.0 |
added 453 characters in body
|
| Jul 28, 2017 at 16:34 | comment | added | Jason Starr | Objects in the etale site of $BG$ can have more automorphisms than the corresponding objects of the etale site of $\text{Spec}(k)$. | |
| Jul 28, 2017 at 15:00 | comment | added | Jingren Chi | @Niels: I'm also confused by this. What about their etale topos? I guess in general inequivalent sites could give rise to equivalent topos? | |
| Jul 28, 2017 at 7:42 | comment | added | Niels | Something is wrong with your analysis in Question 2. For instance it is clear that if $G$ acts trivially on $A=k$ a field, then $BG$ and $spec(k)$ don't have equivalent étale sites. | |
| Jul 28, 2017 at 4:33 | history | asked | Jingren Chi | CC BY-SA 3.0 |