Green correspondence for blocks
= Green correspondence for blocks
{c}
If $N_G(D)\le H\le G$, <Brauer correspondence> pairs the <blocks of a group algebra> of $RG$ and $RH$ having <defect group of a block> $D$. This is <Green correspondence> for their <bimodules>, with <vertex of an indecomposable module> $\Delta D$ in $G\times G$. The normalizer of $\Delta D$ lies in $H\times H$, and the corresponding restriction and induction have unique summands with that vertex.