Equivariant compactifications of a unipotent group by a smooth projective horospherical variety of Picard number one

Hyukmoon Choi

Cheong proved that if $S$ is a simple Lie group and $P$ is a parabolic subgroup, then $S/P$ admits a unique equivariant compactification of the unipotent radical $N$ of $P$, up to…