The nonlinear propagation of a circularly polarized electromagnetic (CPEM) wave in a strongly magnetized electron-positron-ion plasma is investigated. Two coupled equations describing the interaction between a high-frequency CPEM wave and the low-frequency electrostatic wake field are derived. It is found that the generation of the wake fields partly depends on the presence of the ion species and the external magnetic field. The wake field generation in turn leads to deceleration and frequency down conversion of the electromagnetic pulse.Original Publication:P.K. Shukla, G. Brodin, M. Marklund and Lennart Stenflo, Wake field generation and nonlinear evolution in a magnetized electron-positron-ion plasma, 2008, Physics of Plasmas, (15), 8, 0...