Urgent answer required for these questions please!
(3) Let G be a finite group and let element a in Aut(G) be an automorphism og G. Let X be an element of Irr(G) be an irreducible character of G.
Define (X)^a(g) := X(g^a). Is (X)^a irreducible?
Urgent answer required for these questions please!
(3) Let G be a finite group and let element a in Aut(G) be an automorphism og G. Let X be an element of Irr(G) be an irreducible character of G.
Define (X)^a(g) := X(g^a). Is (X)^a irreducible?
Think back to what irreducible characters are--they are the characters of irreps on. So, let
and let
be the irrep it came from. Then, as you can easily verify
as you denoted is the character of
(which is a representation since
). Now, if
left any non-trivial proper subspace of
![]()
-invariant wouldn't it be necessary (using the fact that
is bijective) that same subspace would be
-invariant? So...