On Thursday, January 30, 2014 2:44:10 PM UTC+1, John Cremona wrote:
>
> 1. We use pari's SEA for elliptic curves over prime fields.  the next 
> version of pari, 2.7, is supposed to have point-counting over 
> non-prime fields. 
>
Yes for elliptic curves PARI 2.7 will have SEA over non-prime field (I 
think there is some limitation which makes it unsuitable for small (but not 
so small) characteristic, don't really remember what), and fast canonical 
lift algorithms for small char (when X_0(N) has genus 0, and should have 
quite quickly the same when X_0(N)/W_N has genus 0 as well, maybe more 
later). 
PARI 2.6.2 which should be an RC for PARI 2.7 should be out real soon, at 
least that's what was announced at the latest PARI workshop a few weeks 
ago, so we could begin packaging it.

> 2. There is also very good code out there for hyperelliptics, I think 
> by Sutherland. 
>
There is hypellfrob by David Harvey which is awfully fast, but does not 
work for midly small characteristic when the genus is high.
It's available in Sage, by the way some tickets enhancing the interface or 
related functions need review: #15148 and #11980.
To circumvent the liumiataion of Harvey's algorithm, we would need an 
implementation of the plain Kedlaya algorithm and the char 2 variation by 
Denef Vercauteren.

For non-prime field with moderate characteristic, we would also need some 
method using deformation theory.
There is C code on top of FLINT (2.3) by Pancratz but it targets higher 
dimensional hypersurfaces.

>
> Do you need more general curves than that? 
>
Nope.

-- 
You received this message because you are subscribed to the Google Groups 
"sage-devel" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to sage-devel+unsubscr...@googlegroups.com.
To post to this group, send email to sage-devel@googlegroups.com.
Visit this group at http://groups.google.com/group/sage-devel.
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to