Ticket #8248 (closed enhancement: fixed)
Small improvement in checking for elliptic curve isogenies
|Reported by:||cremona||Owned by:||cremona|
|Report Upstream:||N/A||Reviewers:||Chris Wuthrich|
|Authors:||John Cremona||Merged in:||sage-4.3.3.alpha1|
When an isogeny is constructed from a kernel polynomial, by default (unless check=False) it is checked whether the given kernel polynomial divides the appropriate division polynomial. This is expensive when the degree is large (e.g. 163!).
We provide a small patch which does this checking more efficiently.
The example in the patch which now takes 20s, used to take many minutes.
- Status changed from new to needs_review
- Reviewers set to Chris Wuthrich