As a matter of tension -- kinetic energy spectra in MHD turbulence
  Magnetized turbulence is ubiquitous in many astrophysical and terrestrial
systems but no complete, uncontested theory even in the simplest form,
magnetohydrodynamics (MHD), exists. Many theories and phenomenologies focus on
the joint (kinetic and magnetic) energy fluxes and spectra. We highlight the
importance of treating kinetic and magnetic energies separately to shed light
on MHD turbulence dynamics. We conduct an implicit large eddy simulation of
subsonic, super-Alfv\'enic MHD turbulence and analyze the scale-wise energy
transfer over time. Our key finding is that the kinetic energy spectrum
develops a scaling of approximately $k^{-4/3}$ in the stationary regime as the
kinetic energy cascade is suppressed by magnetic tension. This motivates a
reevaluation of existing MHD turbulence theories with respect to a more
differentiated modeling of the energy fluxes.
