Stable discrete representation of relativistically drifting plasmas
  Representing the electrodynamics of relativistically drifting particle ensembles in discrete, co-propagating Galilean coordinates enables the derivation of a Particle-in-Cell algorithm that is intrinsically free of the Numerical Cherenkov Instability, for plasmas flowing at a uniform velocity. Application of the method is shown by modeling plasma accelerators in a Lorentz-transformed optimal frame of reference. 
Manuel Kirchen, Remi Lehe, Brendan B. Godfrey, Irene Dornmair, Soeren   Jalas, Kevin Peters, Jean-Luc Vay, Andreas R. Maier
physics.plasm-ph