[GAP Forum] decomposing regular representation + (AREP package)

[Vahid Dabbaghian-Abdoly]

Dear R.N. and GAP forum,

I am the author of the REPSN package. REPSN is a package for constructing
complex matrix representations of finite groups. Using this package one can
compute an equivalent block diagonal representation of a given reducible
representation. 

There was a bug in its version 2.0 that I have fixed that and the new
version will be on the web by the end of this week. But if you want I can
send you its zip file.

In the following example you see how to find an equivalent block diagonal
representation of a regular representation of a group:


gap> g := SmallGroup( 6, 1 );;
gap> G := Image(IsomorphismPermGroup( g ));;
gap> H := TrivialSubgroup( G );;
gap> chi := TrivialCharacter( H );;
gap> Hrep := IrreducibleAffordingRepresentation( chi );;
gap> rep := InducedSubgroupRepresentation( G, Hrep );;		
gap> EquivalentBlockRepresentation( rep );
....

This gives you an equivalent block diagonal representation of rep. 

If you have any question you can send me a direct e-mail.

Regards
Vahid



__________________________
Department of Mathematics
Simon Fraser University
8888 University Drive
Burnaby, British Columbia	
V5A 1S6   Canada
E-mail: vdabbagh at sfu.ca
http://www.sfu.ca/~vdabbagh