Exact scaling laws for helical three-dimensional two-fluid turbulent plasmas

TL;DR

This paper derives exact, anisotropic scaling laws for helical two-fluid plasma turbulence, linking invariants like energy and helicity to measurable correlation functions, aiding interpretation of solar wind data and simulations.

Contribution

It introduces new exact scaling laws for helical two-fluid plasmas without assuming isotropy, connecting invariants to two-point correlation functions.

Findings

Derived explicit scaling laws for energy and helicity.

Predicted magnetic energy and electron helicity spectra across scales.

Applicable to solar wind measurements and numerical simulations.

Abstract

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 expressed in terms of the velocity field of each species and the magnetic field. These variables are appropriate for comparison with \textit{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.