[GAP Forum] Scalar subgroup

[Alexander Hulpke]

Dear Forum,

> On Mar 2, 2015, at 3/2/15 3:35, Anvita <anvita21 at gmail.com> wrote:

> Suppose G is a matrix group. What would be
> an efficient way to find the subgroup of G that
> consists of scalar matrices? I have not found
> a suitable function in GAP. Of course, it is
> a subgroup of the centre of G, but it can be
> much smaller than that.

In the cases I have worked with, getting the centre, and then if necessary testing membership of scalar matrices (i.e. subgroups of F*) in the centre would have worked without problems. What dimension, what fields are you looking at?

Regards,

   Alexander Hulpke