Stability conditions for preprojective algebras and root systems of   Kac-Moody Lie algebras
  The aim of this paper is to study the space of stability conditions on the bounded derived category of nilpotent modules over the preprojective algebra associated with a quiver without loops. We describe this space as a covering space of some open set determined by the root system of the Kac-Moody Lie algebra associated with the quiver. 
Akishi Ikeda
math.RT math.AG