Unipotent radical
= Unipotent radical
{title2=$R_u(G)$}
It is the largest connected normal unipotent <subgroup> of a <linear algebraic group>. A connected <reductive algebraic group> has trivial unipotent radical. The <subgroup> $1+J(E)$ of a finite-dimensional algebra's unit group is closed, connected and unipotent.