> < ^ Date: Wed, 05 Feb 2003 14:42:41 +0100 (CET)
> < ^ From: Joachim Neubueser <joachim.neubueser@math.rwth-aachen.de >
^ Subject: re Isotropy subgroups

Dear GAP-forum,

In a letter of Jan. 27 Nicolo Sottocornola asked the GAP Forum:

let G be the subgroup of SO(4) generated by exp(t K), t in R and 
B = diag(1,1,-1,-1).

K is the matrix

[0, -1, -1, 3]
[1, 0, -1, -3]
[1, 1, 0, 3]
[-3, 3, -3, 0].

Is it possible to study continuos group like this with GAP?

Here is my problem. Maybe someone can provide help (with or without GAP).

Let "a" be a real number and consider the point P=(cos(a), sin(a), 0, 0).

I think that, if "a" is not a multiple of pi/2, then the isotropy
subgroup of P is {Id, B}.

Is it true?

Thanks Nicola.

PS The isotropy subgroup of P is {g in G s.t. g(P)=P}. 

So far no Forum member has answered and also a reminder around the GAP
team did not produce any reaction. So it appears that unfortunately
GAP cannot help answer this question. Continuous groups are a topic
really not covered by GAP.

May I recomend, however, to send this query to the group-pub-forum,
which is read by a wider community of group theorists.

Sorry, we can't help this time, Joachim Neubueser

Miles-Receive-Header: reply

> < [top]