In [5], Navarro defines the set
Irr(G|Q,d)\subseteqq Irr(G)\hbox{Irr}(G|Q,\delta)\subseteqq \hbox{Irr}(G)
, where
Q is a
p-subgroup of a
p-solvable group
G, and shows that if δ is the trivial character of
Q, then Irr(
G|
Q, δ) provides a set of canonical lifts of IBr
p(
G), the irreducible Brauer characters with vertex
Q. Previously, in [2], Isaacs defined a canonical set of lifts
Bπ(
G) of
Iπ(
G). Both of these results extend the Fong-Swan Theorem to π-separable groups, and both construct canonical sets of lifts of
the generalized Brauer characters. It is known that in the case that 2∈π, or if |
G| is odd, we have
Bπ(
G) = Irr(
G|
Q, 1
Q). In this note we give a counterexample to show that this is not the case when
2 Ï p2\notin \pi
. It is known that if
N\triangleleft GN\triangleleft G
and χ∈
Bπ(
G), then the constituents of χ
N are in
Bπ (
N). However, we use the same counterexample to show that if
N\triangleleft GN\triangleleft G
, and χ∈Irr(
G|
Q, 1
Q) is such that θ ∈Irr(
N) and [θ, χ
N] ≠ 0, then it is not necessarily the case that θ ∈Irr(
N) inherits this property.
Mathematics Subject Classification (2000). Primary 20C20
Received: 17 October 2005