Processing math: 100%
Ask Your Question
0

Specifying cardinality for action of permutation group

asked 13 years ago

Cody gravatar image

updated 13 years ago

In Magma, it is possible to create a permutation group with something like G := PermutationGroup<n|relations>, where n is to be the cardinality of the set the group acts on. One needs this cardinality to use a GModule method. I would like to create such a group in Sage and then port it to Magma to create a GModule, but I always end up with a Magma element having too small a cardinality. Is it possible to specify such a cardinality in Sage? Can it be created as a subgroup of Sn? I did not have luck with that.

Preview: (hide)

1 Answer

Sort by » oldest newest most voted
2

answered 13 years ago

Mike Hansen gravatar image

updated 13 years ago

niles gravatar image

In ticket 10335, there is a patch which will allow one to specify the domain of the permutation group (and hence its cardinality). For example, you'll be able to do something like

sage: P = PermutationGroup([[(1,2)], [(1,3),(2,4)]], domain=[1,2,3,4,5])
sage: P.degree()
5

where as now in Sage you would get 4 for the degree. This will also be passed on to Magma. I'm hoping that this will be in the next release of Sage.

Preview: (hide)
link

Comments

Thanks! Can you point me a reference on how to apply the patches?

Cody gravatar imageCody ( 13 years ago )

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

Stats

Asked: 13 years ago

Seen: 423 times

Last updated: Jun 22 '11