Kinetic Simulations of Imbalanced Turbulence in a Relativistically-hot Plasma

Turbulent high-energy astrophysical systems often feature asymmetric energy injection or driving: for instance, nonlinear interactions between Alfvén waves propagating from an accretion disk into its corona. Such systems---relativistic analogs of the solar wind---are "imbalanced": the energy fluxes parallel and anti-parallel to the large-scale magnetic field are unequal and the plasma possesses net cross-helicity. In the past, numerical studies of imbalanced turbulence have focused on the magnetohydrodynamic regime. In the present study, we investigate externally-driven imbalanced turbulence in a collisionless, ultrarelativistically hot, magnetized pair plasma using three-dimensional particle-in-cell simulations. We find that a turbulent cascade forms for every value of imbalance covered by the simulations and that injected Poynting flux efficiently converts into net momentum of the plasma, with implications for the launching of a disk wind. Surprisingly, particle acceleration remains efficient even for very imbalanced turbulence. These results characterize properties of imbalanced turbulence in a collisionless plasma and have ramifications for black hole accretion disk coronae, winds, and jets.