False alarm -- the current version of Safe computes this correctly,
presumably because of the bugfix I made.
So this is no longer a Sage issue, but the LMFDB will need to be corrected.
John
On Wed, 1 May 2024 at 08:51, John Cremona wrote:
> This looks like the same bug as I reported at
> https
This looks like the same bug as I reported at
https://github.com/sagemath/sage/issues/36780 five months ago and
supposedly fixed via a PR (https://github.com/sagemath/sage/pull/36786).
It's the same bug (over Q(sqrt(5)), j=0, missing a 5-isogeny) so clearly my
fix was incorrect.
The curve is defin
I can confirm that your curve is isogenous (and not isomorphic) to the ones
in the LMFDB. The isogeny class computed by Sage from your curve has 6
curves in it. That means that there is a bug in Sage's isogeny class code
-- which I wrote most of. I hope that it is something specific to
j-invaria
