Rankin Cohen brackets for (quasi) modular forms for Hecke triangle groups

[a1dd0ea6-9300-4f97-bb3c-0f25ba420caf]

This ticket adds support for Rankin Cohen brackets for (quasi) modular forms:

• http://arxiv.org/abs/math/0509653
• http://arxiv.org/abs/1306.3634v2
• http://math.univ-bpclermont.fr/~royer/ens/Mali/M2_Mali.html

The ticket also adds support for listing the homogeneous and quasi parts of an element and fixes some bugs.

CC: @sagetrac-mraum @videlec @JohnCremona

Component: modular forms

Keywords: modular forms hecke triangle groups rankin cohen bracket

Author: Jonas Jermann

Branch/Commit: u/jj/rankin_cohen_bracket @ 2de1a1b

Issue created by migration from https://trac.sagemath.org/ticket/17909

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

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

59e9bd8	add the multiplication-by-weight operator
fde5a73	initial version of Rankin Cohen brackets
714307e	add missing doctests and documentation
7c4ff2e	apply modern import commit from chapoton
3692cbd	use submodule_with_basis instead of submodule, so that coordinate vectors really correspond to the specified basis, bugfix regarding exception
173ffb2	make series interpretation work more generally with basic validation, allow trivial series in rationalize_series, don't forget denom_factor
85c03e3	adjustments after review

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

Changed commit from 85c03e3 to 884e7a9

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

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

51de4fa	add the multiplication-by-weight operator
1811688	initial version of Rankin Cohen brackets
443e5f1	add missing doctests and documentation
4355e1f	apply modern import commit from chapoton
a9158e5	use submodule_with_basis instead of submodule, so that coordinate vectors really correspond to the specified basis, bugfix regarding exception
3547b2f	make series interpretation work more generally with basic validation, allow trivial series in rationalize_series, don't forget denom_factor
884e7a9	adjustments after review

[embray]

comment:38

Ticket retargeted after milestone closed (if you don't believe this ticket is appropriate for the Sage 8.8 release please retarget manually)

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

Changed commit from 884e7a9 to b704800

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

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

1c32a9c	add the multiplication-by-weight operator
19cc17f	initial version of Rankin Cohen brackets
7f0994e	add missing doctests and documentation
af364ff	apply modern import commit from chapoton
4bb002a	use submodule_with_basis instead of submodule, so that coordinate vectors really correspond to the specified basis, bugfix regarding exception
6d21480	make series interpretation work more generally with basic validation, allow trivial series in rationalize_series, don't forget denom_factor
b704800	adjustments after review

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

Branch pushed to git repo; I updated commit sha1. New commits:

38a56ab

import reduce from functools

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

Changed commit from b704800 to 38a56ab

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

Changed commit from 38a56ab to 40e4b94

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

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

93ff788	add the multiplication-by-weight operator
b626128	initial version of Rankin Cohen brackets
4405776	add missing doctests and documentation
6815521	apply modern import commit from chapoton
d206d0f	use submodule_with_basis instead of submodule, so that coordinate vectors really correspond to the specified basis, bugfix regarding exception
b69818c	make series interpretation work more generally with basic validation, allow trivial series in rationalize_series, don't forget denom_factor
65ecd1b	adjustments after review
40e4b94	import reduce from functools

[a1dd0ea6-9300-4f97-bb3c-0f25ba420caf]

Description changed:

--- 
+++ 
@@ -1,20 +1,10 @@
 This ticket adds support for Rankin Cohen brackets for (quasi) modular forms.
-The formulas shouldn't change for Hecke triangle groups.
-
-The ticket also adds support for listing the homogeneous and quasi parts of an element and fixes some bugs.

 See:
-
 - http://arxiv.org/abs/math/0509653
 - http://arxiv.org/abs/1306.3634v2

 Also see:
 http://math.univ-bpclermont.fr/~royer/ens/Mali/M2_Mali.html

-Possible Todos:
-- Review the definition for more general analytic types (quasi weak/meromorphic forms)
-- Restrict/validate the parameters s, t
-- Review the algebraic structure of the bracket:
-  If s or t is None the bracket is no longer bilinear but it satisfy a Leibnitz rule?
-- Explore alternative brackets
-- Extend the definition from form spaces to form rings?
+The ticket also adds support for listing the homogeneous and quasi parts of an element and fixes some bugs.

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

Changed commit from 40e4b94 to 2de1a1b

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

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

6c33132	add the multiplication-by-weight operator
85c3632	initial version of Rankin Cohen brackets
69d5929	add missing doctests and documentation
68d07d6	apply modern import commit from chapoton
6cb5754	use submodule_with_basis instead of submodule, so that coordinate vectors really correspond to the specified basis, bugfix regarding exception
48a06c1	make series interpretation work more generally with basic validation, allow trivial series in rationalize_series, don't forget denom_factor
86c37a8	adjustments after review
2de1a1b	import reduce from functools

[a1dd0ea6-9300-4f97-bb3c-0f25ba420caf]

Description changed:

--- 
+++ 
@@ -1,10 +1,6 @@
-This ticket adds support for Rankin Cohen brackets for (quasi) modular forms.
-
-See:
+This ticket adds support for Rankin Cohen brackets for (quasi) modular forms:
 - http://arxiv.org/abs/math/0509653
 - http://arxiv.org/abs/1306.3634v2
-
-Also see:
-http://math.univ-bpclermont.fr/~royer/ens/Mali/M2_Mali.html
+- http://math.univ-bpclermont.fr/~royer/ens/Mali/M2_Mali.html

 The ticket also adds support for listing the homogeneous and quasi parts of an element and fixes some bugs.

[a1dd0ea6-9300-4f97-bb3c-0f25ba420caf]

New commits:

6c33132	add the multiplication-by-weight operator
85c3632	initial version of Rankin Cohen brackets
69d5929	add missing doctests and documentation
68d07d6	apply modern import commit from chapoton
6cb5754	use submodule_with_basis instead of submodule, so that coordinate vectors really correspond to the specified basis, bugfix regarding exception
48a06c1	make series interpretation work more generally with basic validation, allow trivial series in rationalize_series, don't forget denom_factor
86c37a8	adjustments after review
2de1a1b	import reduce from functools

[a1dd0ea6-9300-4f97-bb3c-0f25ba420caf]

comment:45

The ticket is in status needs review since 4 years. Will it never be reviewed/merged?

[embray]

comment:46

Ticket retargeted after milestone closed

[mkoeppe]

comment:47

Batch modifying tickets that will likely not be ready for 9.1, based on a review of the ticket title, branch/review status, and last modification date.

[fchapoton]

comment:48

red branch

[a1dd0ea6-9300-4f97-bb3c-0f25ba420caf]

comment:49

Why did this change to needs_work? It was green the last time I worked on it and it was ready for review since over 5 years (it keeps breaking over time for other changes in sage and I have to keep fixing it :(). Also I somehow don't find my branch anymore??

I'm just a bit frustrated with the process here...

[fchapoton]

comment:50

Hello,

I set the ticket to "needs works" because the branch turned red, which indicates a merge conflict with the latest beta release.

I can hear and understand your frustration. Because we are so few active people, it is very difficult for authors of tickets to get their code reviewed. And even more because of the mathematical nature of the tickets, that requires some mathematical understanding from the reviewer. It seems that most of the people that were very active on modular forms at the beginning of sage have left the boat, and turned to other interests.

Maybe you could contact people active with lmfdb.org and ask them if they could find somebody (some expert) to review your ticket ? I have added John Cremona in cc here ; maybe he can help somehow.

[a1dd0ea6-9300-4f97-bb3c-0f25ba420caf]

comment:51

Oh wow, that was a fast answer. I am no longer in academics since ~5 years, I now work as a software engineer. So I don't need this to be merged. I just wanted to provide the work to sage / not to just get lost. If someone is still interested to have it merged I can fix it again. It seems the way how to handle git has changed. What do I do to checkout my branch + fix/push it?

[mkoeppe]

comment:53

Setting new milestone based on a cursory review of ticket status, priority, and last modification date.

[mkoeppe]

comment:54

Setting a new milestone for this ticket based on a cursory review.