#12866 closed defect (fixed)
Bug in Sage's monodromy pairing on elements of Brandt modules
Reported by:  aly.deines  Owned by:  craigcitro 

Priority:  major  Milestone:  sage7.4 
Component:  modular forms  Keywords:  Brandt module, monodromy pairing 
Cc:  Merged in:  
Authors:  Aly Deines, Gonzalo Tornaría  Reviewers:  Frédéric Chapoton 
Report Upstream:  N/A  Work issues:  
Branch:  448cd9d (Commits, )  Commit:  
Dependencies:  Stopgaps: 
Description
In Magma:
Br:=BrandtModule(2,7); g:=Br.1Br.2; InnerProduct(g,g); 6
In Sage:
Br = BrandtModule(2,7) g1,g2 = Br.basis() g = g1g2 print g1,g2 print g.monodromy_pairing(g) (1, 0) (0, 1) 2
Change History (17)
comment:1 Changed 8 years ago by
 Milestone changed from sage5.11 to sage5.12
comment:2 Changed 7 years ago by
 Branch set to u/aly.deines/ticket/12866
 Created changed from 04/21/12 21:08:48 to 04/21/12 21:08:48
 Modified changed from 08/13/13 15:35:53 to 08/13/13 15:35:53
comment:3 Changed 7 years ago by
 Milestone changed from sage6.1 to sage6.2
comment:4 Changed 7 years ago by
 Milestone changed from sage6.2 to sage6.3
comment:5 Changed 7 years ago by
 Milestone changed from sage6.3 to sage6.4
comment:6 Changed 7 years ago by
 Branch changed from u/aly.deines/ticket/12866 to u/tornaria/ticket/12866
 Commit set to cede6e19f33191c6542490a67adb729564b6c627
 Status changed from new to needs_review
comment:7 Changed 7 years ago by
comment:8 Changed 6 years ago by
 Stopgaps set to todo
comment:9 Changed 5 years ago by
 Branch changed from u/tornaria/ticket/12866 to public/12866
 Commit changed from cede6e19f33191c6542490a67adb729564b6c627 to 8cb36d5cfd034995a08c5403b293185843641ac7
I have made a branch with other changes to the file:
 many doc enhancements, and problems corrected
 use of cached_method instead of custom cache
 other small code changes.
New commits:
fcf022a  Merge branch 'u/tornaria/ticket/12866' into 7.1.rc0

8cb36d5  trac #12866 general spring cleanup of doc of Brandt modules

comment:10 Changed 5 years ago by
 Milestone changed from sage6.4 to sage7.1
comment:11 Changed 5 years ago by
comment:12 Changed 5 years ago by
 Milestone changed from sage7.1 to sage7.2
 Stopgaps todo deleted
comment:13 Changed 5 years ago by
 Commit changed from 8cb36d5cfd034995a08c5403b293185843641ac7 to 448cd9de8e322e7f00c86f0d6e51ffeefd83bdaa
Branch pushed to git repo; I updated commit sha1. New commits:
448cd9d  Merge branch 'public/12866' into 7.3.rc0

comment:14 Changed 5 years ago by
 Milestone changed from sage7.2 to sage7.4
comment:15 Changed 5 years ago by
 Reviewers set to Frédéric Chapoton
 Status changed from needs_review to positive_review
I have checked the code of the authors. My own changes are purely cosmetic, and I have doublechecked them. The bot has given a green light.
Therefore I am going to set this to positive review.
comment:16 Changed 5 years ago by
 Branch changed from public/12866 to 448cd9de8e322e7f00c86f0d6e51ffeefd83bdaa
 Resolution set to fixed
 Status changed from positive_review to closed
comment:17 Changed 4 years ago by
 Commit 448cd9de8e322e7f00c86f0d6e51ffeefd83bdaa deleted
Note: See
TracTickets for help on using
tickets.
I rebased Aly's patch to sage6.4.beta1. I added a series of commits to fix a typo in her patch, add some explanation of the computation that is being done, and then an asymptotic improvement so that the monodromy pairing can be computed in O(n) rather than O(n^{2}) ideal computations.
New commits:
Fixed Brandt module monodromy weights.
Fix Aly patch for Brandt module monodromy weights.
Brandt modules: extend _ideal_products() method
Trac 12866: improve asymptotic of monodromy_weights()