Timeline for Automorphisms of curves in positive characteristic
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
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| Oct 24, 2015 at 14:59 | vote | accept | CommunityBot | ||
| Oct 20, 2015 at 14:55 | answer | added | Ariyan Javanpeykar | timeline score: 6 | |
| Oct 20, 2015 at 13:52 | comment | added | Jason Starr | Yes, that is still true. The group scheme of automorphisms of curves of genus $g \geq 2$ is a priori bounded, since the representation on the vector space of global sections of the third power of the dualizing sheaf is faithful. Thus, you may base change to an uncountable field. Now consider a general deformation of a hyperelliptic curve branched over a general configuration of $2g+2$ points in $\mathbb{P}^1$. The only nontrivial automorphism of the hyperelliptic curve is the involution. For $g\geq 3$, under a general first-order deformation, the involution does not extend. | |
| Oct 20, 2015 at 13:45 | history | asked | user68440 | CC BY-SA 3.0 |