Abelian ideals of a Borel subalgebra and root systems

Dmitri I. Panyushev

Let $g$ be a simple Lie algebra and $Ab$ the poset of non-trivial abelian ideals of a fixed Borel subalgebra of $g$. In 2003 (IMRN, no.35, 1889--1913), we constructed a partition o…