Timeline for Is any simple abelian variety covered by a non-simple abelian variety
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 1, 2012 at 14:55 | vote | accept | Harry | ||
| Aug 1, 2012 at 14:53 | comment | added | Donu Arapura | To elaborate: If $f:B\to A$ is finite and separable (e.g. if $char\, k=0$) then Riemann-Hurwitz implies that the ramification divisor $R= K_A-f^*K_B=0$. Therefore $f$ is etale. | |
| Aug 1, 2012 at 14:10 | comment | added | Will Sawin | In case this wasn't clear: a finite homomorphism is necessarily etale since if it etale over one point it is etale over every point, and finite morphisms are etale on a nonempty open subset, thus it is an isogeny. | |
| Aug 1, 2012 at 13:57 | history | answered | inkspot | CC BY-SA 3.0 |