Turbulence in magnetized pair plasmas*

Alfvénic-type turbulence in strongly magnetized, low-beta pair plasmas is investigated [N.F. Loureiro and S. Boldyrev, arXiv:1805.09224 (2018)]. A coupled
set of equations for the evolution of the magnetic and flow potentials are derived, covering both fluid
and kinetic scales. In the fluid (MHD) range those equations are the same as for electron-ion plasmas,
so turbulence at those scales is expected to be of the Alfvénic nature, exhibiting critical balance,
dynamic alignment, and transition to a tearing mediated regime at small scales.
The critical scale at
which a transition to a tearing-mediated range occurs is derived, and the spectral slope in that range
is predicted to be $k_\perp^{-8/3}$ (or $k_\perp^{-3}$, depending on details of the reconnecting configuration assumed). 
At scales below the electron (and positron) skin depth, it is argued that turbulence is dictated by a cascade of the inertial Alfvén wave, which we show to result in the magnetic energy spectrum $\propto k_\perp^{-11/3}$.