On splitting augmentation ideals
On splitting augmentation ideals
Let $G$ be a group, $H$ a subgroup of $G$ and $R$ an associative ring. Write $\omega (RG)$ for the augmentation ideal of the group ring $RG$, and $\omega (RH)G$ for the right ideal of $RG$ generated by $\omega (RH)$. For $G$ finitely generated over $H$ we characterize, in terms …