Permutation character of a coset action
= Permutation character of a coset action
For a subgroup $H\leq G$, the permutation character of the <coset action> on $G/H$ is the induced trivial character
$$
\pi_{G/H}=1_H\mathbin{\uparrow}^G,
$$
and
$$
\pi_{G/H}(g)
=|\{xH:gxH=xH\}|
=\frac1{|H|}|\{x\in G:x^{-1}gx\in H\}|.
$$