Feit numbers and $p'$-degree characters

Abstract

Suppose that $\chi$ is an irreducible complex character of $G$ and let $f_\chi$ be the smallest integer $n$ such that the cyclotomic field $\mathbb Q_n$ contains the values of $\chi$. Let $p$ be a prime, and assume that $\chi \in \textrm{Irr}(G)$ has degree not divisible by $p$. If $G$ is solvable and $\chi(1)$ is odd, then there exists $g \in {\bf N}_G(P) /P'$ with $o(g)=f_\chi$. In particular $f_\chi$ divides $|{\bf N}_G(P) /P'|$.