#13100: EllipticCurve_from_j (over QQ) should not always compute minimal twist
-------------------------------+--------------------------------------------
Reporter: cremona | Owner: cremona
Type: enhancement | Status: new
Priority: minor | Milestone: sage-5.1
Component: elliptic curves | Keywords: elliptic curve construction
Work issues: | Report Upstream: N/A
Reviewers: | Authors:
Merged in: | Dependencies:
Stopgaps: |
-------------------------------+--------------------------------------------
Currently when constructing an elliptic curve from a j-invariant over QQ,
a curve with minimal conductor is created (the so-called "minimal twist").
This could be expensive since it involves factoring j and j-1728, so an
option to *not* find the minimal twist should be allowed, with the current
behaviour as default for backwards compatibility.
For example:
{{{
sage: EllipticCurve(j=2^256+1)
}}}
currently triggers factorization of {{{F_8}}} (which is quite quick) but
also {{{F_8-1728}}} (which is not).
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/13100>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
