On low-frequency waves and instabilities in QED-strong field plasmas

Plasmas with super-strong magnetic field exceeding the Schwinger (or QED) field are of great scientific interest, thanks astrophysical observations of magnetars as well as to the imminent advances in laser-plasma experiments. Importantly, magnetars, which are neutron stars with magnetic fields of ~1e15 Gauss or stronger, do exist in nature. The QED "corrections" on their magnetospheric plasma can produce and order unity effect. We have developed the theoretical 'QED plasma framework', which allows one to explore such strongly magnetized plasmas systematically. We show that the general structure of plasma eigenmodes (shear and compressible Alfven, X and O electromagnetic waves, whistler waves) remains qualitatively the same. We also provide a qualitative discussion of a beam-plasma instability, which may be relevant for understanding of FRBs from a magnetar.