On the orbits of a Borel subgroup in abelian ideals

Dmitri I. Panyushev

Let $B$ be a Borel subgroup of a semisimple algebraic group $G$, and let $\mathfrak{a}$ be an abelian ideal of $\mathfrak{b}=Lie(B)$. The ideal $\mathfrak{a}$ is determined by certain…