© 1997 by London Mathematical Society
© The London Mathematical Society
Character Quotients for Coprime Acting Groups
Department of Mathematics, University of Florida Gainesville, Florida 32611, USA. E-mail: turull{at}math.ufl.edu
Received 18 March 1996. Revision received 26 April 1996.
Let the finite group A be acting on a finite group G with (|A|, |G|)=1. Let
be the semidirect product of A and G. Let
be a character of
irreducible after restriction to G. In a previous paper by Brian Hartley and the author, we proved that the restriction of
to S belongs to the set C(S) obtained by running over all
that arise in this manner, by assuming, in addition, that G is a product of extraspecial groups. This was proved in general, assuming only some condition on the Green functions of groups of Lie type that is not as yet fully verified. In the present paper, we define the map Q(
): S
C by Q(
)(s)=|CG(s)|/
(s). We prove that Q(
)
C(S) under the same hypotheses. In particular, the character quotient Q(
) is an ordinary character.