Parton Energy Loss in an Unstable Quark-Gluon Plasma
  The energy loss of a fast parton scattering elastically in a weakly coupled quark-gluon plasma is formulated as an initial value problem. The approach is designed to study an unstable plasma, but it reproduces the well known result in the case of an equilibrium plasma. Contributions to the energy loss due to unstable modes are shown to exponentially grow in time. An unstable two-stream system is considered as an example. 
Margaret E. Carrington, Katarzyna Deja and Stanislaw Mrowczynski
hep-ph nucl-th