Scaling and noise-crosscorrelations in a Burgers-like model for Magnetohydrodynamics
نویسنده
چکیده
– We study the effects of crosscorrelations of noises on the scaling properties of the correlation functions in a reduced model for Magnetohydrodynamic (MHD) turbulence [A. Basu, J.K Bhattacharjee and S. Ramaswamy [Eur. Phys. J B 9, 725 (1999)]. We show that in dimension d crosscorrelations with sufficient long wavelength singularity become relevant and take the system to the long range noise fixed point. The crosscorrelations also affect the ratio of energies of the magnetic and velocity fields (Eb/Ev) in the strong coupling phase. In dimension d = 1 the fluctuation-dissipation theorem (FDT) does not hold in presence of short range crosscorrelations. We discuss the possible effects of crosscorrelations on the scaling properties of fully developed MHD turbulence. Numerical studies of MHD turbulence in steady state demonstrate the existence of scaling and multiscaling properties of the structure functions [1, 2] which are different from fluid turbulence. The ratio Eb/Ev ≡ ∫
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