John Cremona on Tue, 24 Jun 2014 10:49:44 +0200


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Re: ellheegner


As far as I know, ellheegner was written (based on earlier code by
various people including me, Delaunay, Watkins) for the primary use
case (needed by me!) of finding rational points on rank 1 curves over
Q, without caring which discriminants were used to get there or any
other internal details.

By contrast, the Heegner functions in Sage were written by various
Stein students (mainly Robert Bradshaw I think) who did not care about
the trace to Q, but on more algebraic aspects.

I'm sure that in both cases one could extend the functionality offered
to the user.

John

On 23 June 2014 20:07, Ariel Martin Pacetti <apacetti@dm.uba.ar> wrote:
>
> Dear users,
>
> is there a way to compute a rational heegner point chosing the discriminant?
> This should be implemented in the ellheegner routine, but such choice is not
> available (is there a reason for that?). I remember this was done in an old
> package from Peter Green.
>
> I also noted that sage does not compute the trace of a rational point to Q
> either (this is quite useful for example to show some coefficients of a half
> integral weight modular form, using G-K-Z).
>
> Ariel
>
>