Tests of Nonlinear Interactions Between Alfv\'{e}n Waves Using Gyrokinetic Simulation

Nonlinear interactions between Alfv\'{e}n waves are the fundamental action responsible for plasma turbulence, governing energy transport across a wide range of scales and in nearly any plasma environment. MHD theory predicts that turbulent transport in magnetized plasmas occurs as the result of nonlinear interactions between Alfv\'{e}n waves propagating oppositely along the mean magnetic field. This theory suggests a mechanism for these interactions and predicts interaction rates and products. These results from MHD theory have influenced the development of Alfv\'{e}nic turbulence theory, but the MHD approximation does not hold in many plasmas of scientific interest, making it difficult to test the theory by experiment. We present results of a study employing gyrokinetic simulations that test the hypotheses of MHD Alfv\'{e}nic turbulence theory. These simulations, performed with the astrophysical gyrokinetics code AstroGK, enable the construction of MHD approximating conditions without relying explicitly on the assumptions of MHD theory.