The growth of chiral magnetic instability in a large-scale magnetic field

Abstract

The chiral magnetic effect emerges from a miroscopic level, and its interesting consequences have been discussed in relation to the dynamics of the early universe, neutron stars, and quark-gluon plasma. An instability is caused by an anomalous electric current along the magnetic field. We investigate the effects of plasma motion on the instability in terms of linearized perturbation theory. A magnetic field can inhibit magnetohydrodynamic waves to a remarkable degree, and thereby affects the instability mode. We also found that the unstable mode consists of coupling between Alfvén and one of the magneto-Acoustic waves. Therefore, the propagation of a mixed Alfvén wave driven by magnetic tension is very important. The direction of the unperturbed magnetic field favors the wave propagation of the instability mode, when Alfvén speed exceeds sound speed.