Opened 2 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:  sage8.5 
Component:  elliptic curves  Keywords:  
Cc:  Merged in:  
Authors:  Jeroen Demeyer  Reviewers:  Peter Bruin 
Report Upstream:  N/A  Work issues:  
Branch:  123f2b1 (Commits)  Commit:  123f2b102cf43184e1c2bcbd5c956152082ea6f1 
Dependencies:  Stopgaps: 
Description (last modified by )
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 2 years ago by
 Description modified (diff)
comment:2 Changed 2 years ago by
 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 2 years ago by
 Description modified (diff)
comment:4 Changed 2 years ago by
 Branch set to u/jdemeyer/isogenies_prime_degree___does_not_work_well_for_degree___characteristic
comment:5 Changed 2 years ago by
 Commit set to 58726f355fca49e568673900cda5ce7d7062d47c
 Description modified (diff)
 Status changed from new to needs_review
comment:6 Changed 2 years ago by
 Commit changed from 58726f355fca49e568673900cda5ce7d7062d47c to 8957a64c64a9f4ceed8e3c0fee958abb99479a21
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
8957a64  Document better that isogenies_prime_degree() only finds separable isogenies

comment:7 Changed 2 years ago by
 Commit changed from 8957a64c64a9f4ceed8e3c0fee958abb99479a21 to 123f2b102cf43184e1c2bcbd5c956152082ea6f1
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
123f2b1  Document better that isogenies_prime_degree() only finds separable isogenies

comment:8 Changed 2 years ago by
 Description modified (diff)
comment:9 Changed 2 years ago by
 Reviewers set to Peter Bruin
 Status changed from needs_review to positive_review
Definitely an improvement.
comment:10 Changed 2 years ago by
 Milestone changed from sage8.4 to sage8.5
comment:11 Changed 2 years ago by
 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
New commits:
Document better that isogenies_prime_degree() only finds separable isogenies