id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
5674 duplicate of #5673 cremona was "The patch does the following related things:
1. Implements in ell_generic functions is_quadratic_twist(), is_quartic_twist(), is_sextic_twist(), which detect twists between curves (returning the appropriate twisting paramenter)
2. Deprecates the EllipticCurve(j) constructor, replacing it with EllipticCurve_from_j(j). Over Q this gives the minimal twist, i.e. a curve with the correct j and minimal conductor.
3. Rewrites the function minimal_quadratic_twist() introduced in #4667 to use the previous function, with extra work in case j=0, 1728 since we need the minimal __quadratic__ twist, not the minimal twist.
There is likely to be a necessary change to documentation (pages 38 and 39 of the tutorial) which have not yet been made.
The patch is based on 3.4.1.alpha0 + patches at #4667.
I have tested all files in sage/schemes/elliptic_curves. There are two failures in sha_tate which I do not understand, so I am posting the patch anyway.
" enhancement closed minor sage-3.4.1 number theory duplicate elliptic curve twist wuthrich