#18005: Group algebra of nonstandard symmetric groups broken
-------------------------+-------------------------------------------------
Reporter: darij | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.6
Component: | Keywords: symmetric group, group
combinatorics | algebra, permutations
Merged in: | Authors:
Reviewers: | Report Upstream: N/A
Work issues: | Branch:
Commit: | Dependencies: #16926
Stopgaps: |
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I have recorded the problem in #16926. Quoting
src/sage/groups/perm_gps/permgroup_named.py:
{{{
def algebra(self, base_ring):
"""
Return the symmetric group algebra associated to ``self``.
.. WARNING::
This is broken!
sage: S = SymmetricGroup([2,3,5])
sage: S.an_element()
(2,3,5)
sage: S.algebra(QQ)(_)
Traceback (most recent call last):
...
ValueError: The permutation has length 3 but its maximal
element is 5. Some
element may be repeated, or an element is missing, but
there is something
wrong with its length.
Best make it a usual group algebra with none of the bells and
whistles
of the SGA but with functioning methods.
EXAMPLES::
sage: S4 = SymmetricGroup(4)
sage: S4.algebra(QQ)
Symmetric group algebra of order 4 over Rational Field
"""
from sage.combinat.symmetric_group_algebra import
SymmetricGroupAlgebra
return SymmetricGroupAlgebra(base_ring, self)
}}}
--
Ticket URL: <http://trac.sagemath.org/ticket/18005>
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