Low Frequency Electromagnetic Instability in UnmagnetizedInhomogeneous Dusty Plasmas

The low frequency electromagnetic wave instability in an unmagetized inhomogeneous dusty plasma has been pointed out. It has been noticed that there exists a stable mode if the propagation of the wave vector along the density gradient is ignored. However, the mode becomes unstable by including the propagation of the wave in the opposite direction of the density gradient.