Vortices in a strongly magnetized electron-positron-ion plasma

A theoretical investigation has been presented for the linear and nonlinear properties of obliquely propagating coupled low-frequency electrostatic drift and ion-acoustic (ED-IA) waves in a strongly magnetized nonuniform electron-positron-ion plasma in the presence of sheared ion flow. A result front our linear analysis is that the ED-IA waves can be unstable due to the ion sheared flow. In addition. it is shown that the nonlinear equations governing the dynamics of weakly interacting ED-IA waves admit vortex solutions of two different classes viz. a vortex chain and a double vortex.