Characteristic free measure rigidity for the action of solvable groups   on homogeneous spaces
  We classify measures on a homogeneous space which are invariant under a certain solvable subgroup and ergodic under its unipotent radical. Our treatment is independent of characteristic. As a result we get the first measure classification for the action of semisimple subgroups without any characteristic restriction. 
Amir Mohammadi, Alireza Salehi Golsefidy
math.DS math.GR