MHD Turbulence

A remarkable success of the theory of strong MHD turbulence provided an elegant explanation of its main two spectral properties: the spectra perpendicular and parallel to the magnetic field. While the perpendicular spectrum, which is also isotropized spectrum is a conventional Eulerian spatial spectrum of strong turbulence, the parallel spectrum is equivalent to the Lagrangian frequency spectrum. A few claims, however, appeared to challenge this vanilla model. We critically examine these claims by analyzing simulations of Alfvenic turbulence with resolution up to 4096³. In particular, we test 1) whether the so-called dynamic alignment is observed on the appreciable range of scales and 2) whether MHD turbulence have a large number of unstable tangential discontinuities - current layers – that contribute significantly to the energy transfer. So far, we found that the new claims are not well-supported by numerics. Mostly these come from a gross lack of understanding on the nature of numerical limitations and sometimes even misunderstanding of scientific methodology.