A weak turbulence theory for incompressible MHD
  We derive a weak turbulence formalism for incompressible MHD. Three-wave interactions lead to a system of kinetic equations for the spectral densities of energy and helicity. We find energy spectra solution of the kinetic equations. The constants of the spectra are computed exactly and found to depend on the amount of correlation between the velocity and the magnetic field. Comparison with several numerical simulations and models is also made. 
S. Galtier (1,2), S.V. Nazarenko (1), A.C. Newell (1), A. Pouquet (2)   ((1) Mathematics Institute, University of Warwick, (...