Opened 3 years ago

Closed 2 years ago

#26487 closed defect (fixed)

Document that isogenies_prime_degree() only finds separable isogenies

Reported by: jdemeyer Owned by:
Priority: major Milestone: sage-8.5
Component: elliptic curves Keywords:
Cc: Merged in:
Authors: Jeroen Demeyer Reviewers: Peter Bruin
Report Upstream: N/A Work issues:
Branch: 123f2b1 (Commits, GitHub, GitLab) Commit: 123f2b102cf43184e1c2bcbd5c956152082ea6f1
Dependencies: Stopgaps:

Status badges

Description (last modified by jdemeyer)

isogenies_prime_degree only finds separable isogenies, so it never finds the Frobenius. This is not documented very well. It does find the Verschiebung for ordinary elliptic curves but not for supersingular elliptic curves. We clarify this in the documentation. We also add some examples and reorganize the existing examples.

Additionally, we simplify the logic of the isogenies_prime_degree() wrapper a bit.

Change History (11)

comment:1 Changed 3 years ago by jdemeyer

  • Description modified (diff)

comment:2 Changed 3 years ago by jdemeyer

  • Authors set to Jeroen Demeyer
  • Description modified (diff)
  • Summary changed from isogenies_prime_degree() does not work well for degree = characteristic to Document that isogenies_prime_degree() only finds separable isogenies

comment:3 Changed 3 years ago by jdemeyer

  • Description modified (diff)

comment:4 Changed 3 years ago by jdemeyer

  • Branch set to u/jdemeyer/isogenies_prime_degree___does_not_work_well_for_degree___characteristic

comment:5 Changed 3 years ago by jdemeyer

  • Commit set to 58726f355fca49e568673900cda5ce7d7062d47c
  • Description modified (diff)
  • Status changed from new to needs_review

New commits:

​58726f3Document better that isogenies_prime_degree() only finds separable isogenies

comment:6 Changed 3 years ago by git

  • Commit changed from 58726f355fca49e568673900cda5ce7d7062d47c to 8957a64c64a9f4ceed8e3c0fee958abb99479a21

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

​8957a64Document better that isogenies_prime_degree() only finds separable isogenies

comment:7 Changed 3 years ago by git

  • Commit changed from 8957a64c64a9f4ceed8e3c0fee958abb99479a21 to 123f2b102cf43184e1c2bcbd5c956152082ea6f1

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

​123f2b1Document better that isogenies_prime_degree() only finds separable isogenies

comment:8 Changed 3 years ago by jdemeyer

  • Description modified (diff)

comment:9 Changed 2 years ago by pbruin

  • Reviewers set to Peter Bruin
  • Status changed from needs_review to positive_review

Definitely an improvement.

comment:10 Changed 2 years ago by chapoton

  • Milestone changed from sage-8.4 to sage-8.5

comment:11 Changed 2 years ago by vbraun

  • Branch changed from u/jdemeyer/isogenies_prime_degree___does_not_work_well_for_degree___characteristic to 123f2b102cf43184e1c2bcbd5c956152082ea6f1
  • Resolution set to fixed
  • Status changed from positive_review to closed
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