Invariant probability measures and non-wandering sets for impulsive   semiflows
  We consider impulsive dynamical systems defined on compact metric spaces and their respective impulsive semiflows. We establish sufficient conditions for the existence of probability measures which are invariant by such impulsive semiflows. We also deduce the forward invariance of their non-wandering sets except the discontinuity points. 
Jose F. Alves, Maria Carvalho
math.DS