Relativistic nonlinear propagation of laser beams in cold overdense plasmas

The nonlinear propagation of a very intense laser beam in a cold overdense plasma is analytically investigated; the laser beam is assumed to be intense enough to cause the directed component of electron velocity to be comparable to the velocity of light. Special attention has been given to the case when coupled longitudinal-cum-transverse modes propagate in the plasma. An interesting result is that the beam can readily propagate through the overdense plasma, in contrast to what would be expected on the basis of a linear theory of laser propagation