Numerical simulations of imbalanced strong magnetohydrodynamic
  turbulence
  Magnetohydrodynamics (MHD) is invoked to address turbulent fluctuations in a
variety of astrophysical systems. MHD turbulence in nature is often anisotropic
and imbalanced, in that Alfvenic fluctuations moving in opposite directions
along the background magnetic field carry unequal energies. This work
formulates specific requirements for effective numerical simulations of strong
imbalanced MHD turbulence with a guide field B0 High-resolution simulations are
then performed and they suggest that the spectra of the counter-propagating
Alfven modes do not differ from the balanced case, while their amplitudes and
the corresponding rates of energy cascades are significantly affected by the
imbalance. It is further proposed that the stronger the imbalance the larger
the magnetic Reynolds number that is required in numerical simulations in order
to correctly reproduce the turbulence spectrum. This may explain current
discrepancies among numerical simulations and observations of imbalanced MHD
turbulence.
