You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
…ead of just a post-isomorphism when computing dual isogeny
While computing the dual of an isogeny, the current code only searches
for a post-isomorphism which gives the correct scaling factor overall.
In some cases, as shown by sagemath#37168, such an isomorphism may not exist,
and we additionally have to compose with a suitable pre-isomorphism.
This resolvessagemath#37168.
URL: sagemath#37175
Reported by: Lorenz Panny
Reviewer(s): Giacomo Pope, Lorenz Panny
Steps To Reproduce
We create an isogeny between elliptic curves over a finite field of 23^2 elements:
Expected Behavior
The dual of
phi
should be returned.Actual Behavior
The following error is raised:
Additional Information
The error is not raised when
codomain=E1
is omitted.Environment
Checklist
The text was updated successfully, but these errors were encountered: