Hysteresis in Ferromagnetic Random Field Ising Model with an Arbitrary   Initial State
  We present exact expressions for hysteresis loops in the ferromagnetic random field Ising model in the limit of zero temperature and zero driving frequency for an arbitrary initial state of the model on a Bethe lattice. This work extends earlier results that were restricted to an initial state with all spins pointing parallel to each other. 
Prabodh Shukla and R Kharwanlang