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 the dynamics of the early universe, neutron stars and quark-gluon plasma. An instability is caused by anomalous electric current along magnetic field. We investigate 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 is consisted of coupling between Alfvén and one of magneto-acoustic waves. Therefore, the propagation of a mixed Alfvén wave driven by magnetic tension is very important. The direction of unperturbed magnetic field favors the wave propagation of the instability mode, when Alfvén speed exceeds sound speed.