Exact Scaling Laws for Helical Three-dimensional Two-fluid Turbulent Plasmas
Résumé
We derive exact scaling laws for a three-dimensional incompressible helical two-fluid plasma, without the assumption of isotropy. For each ideal invariant of the two-fluid model, i.e. the total energy, the electron helicity and the proton helicity, we derive simple scaling laws in terms of two-point increments correlation functions as a function of the velocity field of each species and the magnetic field. These variables are appropriate for comparison with in-situ measurements in the solar wind at different spatial ranges and data from numerical simulations. Finally, with the exact scaling laws and dimensional analysis we predict the magnetic energy and electron helicity spectra for different ranges of scales.