Opened 15 years ago

Closed 15 years ago

#1183 closed defect (fixed)

[with patch, with positive review] Residue fields are broken

Reported by: roed Owned by: was
Priority: major Milestone: sage-2.9
Component: number theory Keywords:
Cc: Merged in:
Authors: Reviewers:
Report Upstream: Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description

The current implementation of residue fields for number fields is broken. It just takes the defining polynomial for the number field, factors it over Z/pZ, picks one factor and creates an extension using that factor. This breaks because elements of the ring of integers, when expressed in terms of the power basis of the number field can have denominators divisible by p.

The solution is to create a p-maximal order and do some linear algebra to come up with a map that doesn't break on denominators divisible by p. Pari's nfinit has a way to give it a partial factorization of the discriminant that will produce a p-maximal order.

If you want to implement this, talk to William Stein or David Roe for more details.

Attachments (5)

trac-1183-supportforquo-step1and2.patch (15.6 KB) - added by was 15 years ago.
trac-1183-through_step_3.patch (4.2 KB) - added by was 15 years ago.
trac-1138-throughstep4.patch (14.3 KB) - added by was 15 years ago.
further work, but still some issues.…
trac-1183-step5.patch (4.6 KB) - added by was 15 years ago.
trac-1183-step6.patch (16.9 KB) - added by was 15 years ago.

Download all attachments as: .zip

Change History (10)

comment:1 Changed 15 years ago by mabshoff

Ifti did open #1185 for his specific problem. So in case this is solved and the status of #1183 remains unchanged please resolve that ticket, also.

Cheers,

Michael

Changed 15 years ago by was

Changed 15 years ago by was

further work, but still some issues....

comment:2 Changed 15 years ago by was

NOT ready to be released yet.

comment:3 Changed 15 years ago by was

Changed 15 years ago by was

Changed 15 years ago by was

comment:4 Changed 15 years ago by craigcitro

  • Summary changed from Residue fields are broken to [with patch, with positive review] Residue fields are broken

comment:5 Changed 15 years ago by mabshoff

  • Resolution set to fixed
  • Status changed from new to closed

Merged in 2.9.rc0.

Note: See TracTickets for help on using tickets.