Opened 5 years ago

Closed 5 years ago

#23329 closed enhancement (fixed)

Implement characteristic() for ring of coordinate functions

Reported by: jdemeyer Owned by:
Priority: major Milestone: sage-8.0
Component: commutative algebra Keywords:
Cc: ​egourgoulhon, tscrim, ​mbejger Merged in:
Authors: Frédéric Chapoton Reviewers: David Roe
Report Upstream: N/A Work issues:
Branch: 86d0ef3 (Commits, GitHub, GitLab) Commit: 86d0ef324bf5527442247f5c840f6d26957358e7
Dependencies: Stopgaps:

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Description


Change History (10)

comment:1 Changed 5 years ago by jdemeyer

  • Summary changed from Implement characteristic for ring of coordinate functions to Implement characteristic() for ring of coordinate functions

The characteristic should be the characteristic of the K from this documentation: 

r"""
Symbolic Coordinate Functions

In the context of a topological manifold `M` over a topological field `K`,
a *coordinate function*  is a function from a chart codomain
to `K`. In other words, a coordinate function is a `K`-valued function of
the coordinates associated to some chart.

Now please tell me: how does one retrieve the K from the coordinate ring?

On the other hand, the focus on symbolics might imply that the characteristic is always zero, but it would be good if somebody could confirm this.

comment:2 follow-up: Changed 5 years ago by jdemeyer

Thinking more about it, this could be handled in the category of Algebras.

comment:3 in reply to: ↑ 2 Changed 5 years ago by jdemeyer

Replying to jdemeyer:

Thinking more about it, this could be handled in the category of Algebras.

Not really, since you cannot in general know the base ring of an element of Algebras.

comment:4 Changed 5 years ago by chapoton

  • Branch set to u/chapoton/23329
  • Commit set to 86d0ef324bf5527442247f5c840f6d26957358e7
  • Status changed from new to needs_review

New commits:

​86d0ef3trac 23329 characteristic of coordinate chart function ring

comment:5 Changed 5 years ago by chapoton

green bot, please review

comment:6 Changed 5 years ago by roed

  • Reviewers set to David Roe

Looks good to me.

comment:7 Changed 5 years ago by chapoton

so is this a positive review ?

comment:8 Changed 5 years ago by roed

  • Status changed from needs_review to positive_review

Oops, forgot to modify the ticket.

comment:9 Changed 5 years ago by jdemeyer

  • Authors changed from Jeroen Demeyer to Frédéric Chapoton

comment:10 Changed 5 years ago by vbraun

  • Branch changed from u/chapoton/23329 to 86d0ef324bf5527442247f5c840f6d26957358e7
  • Resolution set to fixed
  • Status changed from positive_review to closed
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