Project Leader
Kate
Group Members
Aly, Jenn, Diane, Ekin
Project Description
Associated notebook file KateWishList.sws
Projects are listed by section below. No one is currently working on these ones:
- Compute lots of examples to find guesses for bounds on "C"
- Put Kate's EDS class into sage (document properly)?
Restricted global_minimal_model()
* ticket?
Wrapping E.reduction(prime)(P)
* Ticket needs review! #11822
p-adics
* Implement E.reduction(p) for E defined over a p-adic fields: reduction of elliptic curves over padics.sws
This found a bug/needed enhancement which is now reported: #11826
* Tate's algorithm
Singular Cubics
* Currently the patch on the trac server will allow one to define singular cubics.
sage: E = WeierstrassCubic([0,0,0,0,0]) sage: E.is_singular() True
* Stuff to do:
- Work through elliptic curve documentation, test functions that should work for singular curves, and update the following lists
Document the WeierstrassCubic and SingularWeierstrass classes we've created
- Do the stuff on the list below
- make E.reduction(bad_prime) able to return this singular cubic object
* Functions that seem ok out of the box (so need only documentation adjustment/testing):
- a_invariants() etc. (b, c also)
- discriminant()
- base_ring()
- base_field()
- is_on_curve()
- coordinate_ring()
- division_polynomial()
- formal_group()
- multiplication_by_m()?
* Functions that should do something appropriate but don't (need coding):
- j_invariant() -- should probably return +infinity?
- change_weierstrass_model() -- the new curve needs to pass flag
- base_extend() -- the problem may be my patch didn't work
- change_ring() -- the problem may be my patch didn't work
- cardinality() -- for finite fields
- local stuff....??
- addition of points on a curve (seems to work, but needs to avoid singular point)
* Functions that we should write (new): done - see attached worksheet.
- is_singular() (done) -- this is also accessible as an internal flag: self._is_singular
- P.is_singular_point() -- for a point on the curve
- singularity_type() -- tells you if it's a node or a cusp
- singular_point() -- returns the node or cusp