#21081: Cup product for cochains
----------------------------+----------------------------------
       Reporter:  vbraun    |         Type:  enhancement
         Status:  new       |     Priority:  major
      Milestone:  sage-7.3  |    Component:  algebraic topology
       Keywords:            |    Merged in:
        Authors:            |    Reviewers:
Report Upstream:  N/A       |  Work issues:
         Branch:            |       Commit:
   Dependencies:            |     Stopgaps:
----------------------------+----------------------------------
 It would be nice to have the cup product available for arbitrary cochains,
 without involving `homology_vector_space_with_basis`. Of course its not
 well-defined on the level of cochains, but at least one could check that
 products are non-zero if there is torsion over ZZ etc.

 There are potentially two places where to put it:

 * Method of `Chain.Element`, then chains would need to know about their
 cell (sub)complex. Right now they don't reference their cell complex as
 far as I can see.

 * Method `GenericCellComplex.cup_product(self, left_cochain,
 right_cochain)`. Then chains need to know their degree (dimension of
 cells). Right now they don't store their degree, although the
 documentation says that they must be of homogeneous degree.

 Thoughts?

--
Ticket URL: <https://trac.sagemath.org/ticket/21081>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica, 
and MATLAB

-- 
You received this message because you are subscribed to the Google Groups 
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.

Reply via email to