Timeline for Behaviour of (principal) polarizations of (singular) surfaces under birational maps
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 19, 2018 at 14:31 | vote | accept | Bernie | ||
| Jan 19, 2018 at 12:14 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Dec 20, 2017 at 12:03 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Nov 20, 2017 at 11:12 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Oct 22, 2017 at 6:03 | comment | added | naf | @JasonStarr: I think the OP is actually just trying to ask his earlier question [mathoverflow.net/questions/281677/… in a slightly different way. | |
| Oct 21, 2017 at 11:06 | answer | added | Jason Starr | timeline score: 2 | |
| Oct 21, 2017 at 9:54 | comment | added | Jason Starr | @ulrich Hello again. If the top horizontal arrow is an isomorphism, then the middle arrow is also an isomorphism, since it is just the associated map of Kummer varieties. Of course an Abelian variety can have more than one principle polarization, but my interpretation of the following cryptic sentence is that the OP was focused on regularity of the top morphism, "Do we actually get $(A,D_1)\cong (A_2,D_2)$ under which conditions can we conclude that we have an isomorphism of principally polarized abelian surfaces using this diagram?" | |
| Oct 21, 2017 at 4:34 | comment | added | naf | @JasonStarr: There is no abelian variety in the bottom horizontal arrow so how do you apply Weil's theorem? | |
| Oct 20, 2017 at 13:56 | comment | added | Jason Starr | Every rational transformation from a smooth variety to an Abelian variety is everywhere regular by the Weil extension theorem. Thus, all of your horizontal arrows are isomorphisms. | |
| Oct 20, 2017 at 13:52 | history | asked | Bernie | CC BY-SA 3.0 |