Opened 7 years ago
Closed 7 years ago
#16011 closed defect (fixed)
Fix _torsion_bound() for elliptic curves over relative number fields
Reported by:  pbruin  Owned by:  

Priority:  minor  Milestone:  sage6.2 
Component:  elliptic curves  Keywords:  relative number field ramification 
Cc:  cremona, mmasdeu  Merged in:  
Authors:  Marc Masdeu  Reviewers:  Peter Bruin 
Report Upstream:  N/A  Work issues:  
Branch:  94d6219 (Commits)  Commit:  94d6219e76683651b78fdcf6c176f15fb87f77a1 
Dependencies:  Stopgaps: 
Description
Computing torsion subgroups of elliptic curves over relative number fields fails:
sage: R.<x> = QQ[] sage: F.<a> = QuadraticField(5) sage: K.<b> = F.extension(x^23) sage: E = EllipticCurve(K,[0,0,0,b,1]) sage: E.torsion_subgroup() ... NotImplementedError: For an ideal in a relative number field you must use relative_ramification_index or absolute_ramification_index as appropriate
The solution should be to make E._torsion_bound()
use absolute_ramification_index()
instead of ramification_index()
.
Change History (6)
comment:1 Changed 7 years ago by
 Branch set to u/mmasdeu/torsion_relative_number_fields
 Commit set to 0fab9272cba589ec49a58fe77cf7d4524b6e6cbb
 Status changed from new to needs_review
comment:2 Changed 7 years ago by
Done!
comment:3 Changed 7 years ago by
 Reviewers set to Peter Bruin
 Status changed from needs_review to positive_review
Looks good (and very quick)! One nonessential comment on your patch: the preferred way of referring to Trac tickets is :trac:`16011`
instead of #16011
.
comment:4 Changed 7 years ago by
 Commit changed from 0fab9272cba589ec49a58fe77cf7d4524b6e6cbb to 94d6219e76683651b78fdcf6c176f15fb87f77a1
 Status changed from positive_review to needs_review
Branch pushed to git repo; I updated commit sha1 and set ticket back to needs_review. New commits:
94d6219  Fixed way to refer to ticket.

comment:5 Changed 7 years ago by
 Status changed from needs_review to positive_review
comment:6 Changed 7 years ago by
 Branch changed from u/mmasdeu/torsion_relative_number_fields to 94d6219e76683651b78fdcf6c176f15fb87f77a1
 Resolution set to fixed
 Status changed from positive_review to closed
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New commits:
Fixed torsion_order for relative number fields.