On wave turbulence in MHD

S. Galtier (1) , S. V. Nazarenko (1) , A. C. Newell (1)

1 Mathematics Institute

We describe the fundamental differences between weak (wave) turbulence in incompressible and weakly compressible MHD at the level of three-wave interactions. The main difference is in the structure of the resonant manifolds and the mechanisms of redistribution of spectral densities along the applied magnetic field B₀. Similar to pure acoustic waves, a three-wave resonance between collinear wave vectors is observed but, in addition, we also have a resonance through tilted planes and spheres. The properties of resonances and their consequences for the asymptotics are also discussed.

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]; Sciences de la Terre

S. Galtier, S. V. Nazarenko, A. C. Newell. On wave turbulence in MHD. Nonlinear Processes in Geophysics, 2001, 8 (3), pp.141-150. ⟨hal-00302012⟩