Mean magnetic field renormalization and Kolmogorov's energy spectrum in MHD turbulence

In this paper we construct a self-consistent renormalization group procedure for MHD turbulence in which small wavenumber modes are averaged out, and effective mean magnetic field at large wavenumbers is obtained. In this scheme the mean magnetic field scales as $k^{-1/3}$, while the energy spectrum scales as $k^{-5/3}$ similar to that in fluid turbulence. We also deduce from the formalism that the magnitude of cascade rate decreases as the strength of the mean magnetic field is increased.