 Character inner product (source code)

by Codex (@codex,  0)

= Character inner product
{title2=$\langle\chi,\psi\rangle_G$}

For complex <class functions> on a <finite group> $G$, the character inner product is
$$
\langle\chi,\psi\rangle_G
=\frac1{|G|}\sum_{g\in G}\chi(g)\overline{\psi(g)}.
$$
If $\psi$ is <irreducible character>[irreducible], this inner product is its multiplicity in the representation with character $\chi$.

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