Opened 10 years ago

Closed 10 years ago

Last modified 10 years ago

#11601 closed enhancement (fixed)

Generic congruence subgroups

Reported by: davidloeffler Owned by: craigcitro
Priority: major Milestone: sage-5.0
Component: modular forms Keywords: modular subgroup congruence sd35
Cc: Merged in: sage-5.0.beta1
Authors: David Loeffler Reviewers: Johan Bosman
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: #10335, #11422, #11598, #10453, #5048 Stopgaps:

Status badges

Description (last modified by davidloeffler)

This ticket adds functionality to work with arbitrary congruence subgroups of the modular group (specified by a level N and a subgroup of the finite group SL(2, Z / N Z) ). These support all the basic functionality one would expect: computation of index, genus, elliptic points, cusps, etc. There is also a facility to compute the congruence closure of a (possibly noncongruence) subgroup.

Some "rationalisation" is also included: e.g. one can no longer create Gamma1(1) or GammaH(11, [2]), which previously existed as less-functional duplicates of SL2Z and Gamma0(11). (They previously played a role in "remembering" where certain degeneracy maps would go, but they didn't do this very well -- which was the cause of the issue at #10453 -- and the new more robust approach introduced at #10453 means we can get rid of them at last.)

Part of a series of tickets: #10335 - #11422 - #11598 - #10453 - #5048 - this one - #10546.

Apply 11601.4.patch on top of #5048. Once this is merged, #12001 can be closed as fixed.

Attachments (4)

trac_11601-congroups.patch (46.9 KB) - added by davidloeffler 10 years ago.
Patch against 4.7.1.alpha4 + dependencies as in ticket description
trac_11601-congroups.2.patch (46.0 KB) - added by davidloeffler 10 years ago.
New version rebased for 4.7.2.alpha3
11601.3.patch (46.0 KB) - added by johanbosman 10 years ago.
11601.4.patch (46.0 KB) - added by johanbosman 10 years ago.

Download all attachments as: .zip

Change History (17)

Changed 10 years ago by davidloeffler

Patch against 4.7.1.alpha4 + dependencies as in ticket description

comment:1 Changed 10 years ago by davidloeffler

  • Status changed from new to needs_review

comment:2 Changed 10 years ago by davidloeffler

  • Description modified (diff)

Changed 10 years ago by davidloeffler

New version rebased for 4.7.2.alpha3

comment:3 Changed 10 years ago by davidloeffler

  • Dependencies changed from #10335, #11422, #11598, #5048, #10453 to #10335, #11422, #11598, #10453, #5048
  • Description modified (diff)

comment:4 Changed 10 years ago by johanbosman

  • Status changed from needs_review to needs_work
  • Work issues set to rebase

I tried to apply trac_11601-congroups.2.patch to 4.8.alpha4 + #5048, but it failed.

Changed 10 years ago by johanbosman

comment:5 Changed 10 years ago by johanbosman

  • Work issues changed from rebase to docbuild

I'm getting a warning when building the documentation, in is_CongruenceSubgroup in congroup_generic.py:

    Note that this may be False even if `x` really is a congruence subgroup --
    it tests whether `x` is "obviously" congruence, i.e.~whether it has a
    congruence subgroup datatype. To test whether or not an arithmetic subgroup
    of `SL(2, \ZZ)` is congruence, use the ``is_congruence()` method instead.

I guess a quote is missing at the end of is_congruence().

Changed 10 years ago by johanbosman

comment:6 Changed 10 years ago by johanbosman

  • Description modified (diff)
  • Status changed from needs_work to positive_review

comment:7 Changed 10 years ago by johanbosman

  • Work issues docbuild deleted

comment:8 Changed 10 years ago by johanbosman

  • Reviewers set to Johan Bosman

comment:9 Changed 10 years ago by jdemeyer

  • Milestone changed from sage-4.8 to sage-5.0

comment:10 Changed 10 years ago by davidloeffler

  • Description modified (diff)

comment:11 Changed 10 years ago by davidloeffler

  • Keywords sd35 added

comment:12 Changed 10 years ago by jdemeyer

  • Merged in set to sage-5.0.beta1
  • Resolution set to fixed
  • Status changed from positive_review to closed

comment:13 Changed 10 years ago by davidloeffler

Apply 11601.4.patch

(for the patchbot, so it knows the prerequisites for 11709)

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