Nonlinear effects caused by intense electromagnetic waves in an electron-positron-ion plasma

It is shown that intense radiation nonlinearly interacts with the acousticlike waves in an electron-positron-ion plasma at nonrelativistic temperatures. The interaction is governed by the electromagnetic wave equation including the relativistic electron and positron mass variations and the density changes associated with the acousticlike waves, and an equation for the latter in the presence of the radiation pressure, The governing nonlinear equations are analyzed to show the possibility of a novel modulational instability as well as the formation of light bullets and solitons. (C) 2003 American Institute of Physics.