AC Currents from Gravitational Waves in Plasma Flows

It is well-known that gravitational waves can induce electromagnetic perturbations in magnetised plasmas, with production occurring via the direct coupling of gravitational waves to the background magnetic field: this is the so-called Gertsenshtein effect. In this short work, we consider the direct gravitational perturbations of charge carriers via their minimal coupling to gravity in a collisionless plasma. We find that for isotropic plasmas, no secondary plasma perturbations are generated. However, when an anisotropy is introduced in the form of a background plasma current, we find that gravitational waves can induce a secondary current. For a constant DC background current, the secondary current inherits the AC frequency of the gravitational waves. It will certainly be interesting to investigate this effect in astrophysical plasmas in future work as well as its wider phenomenological consequences.