E.M. solitons and their stability in relativistic degenerate plasmas

Based on a relativistic fluid model coupled to the Maxwell's equations, we investigate the nonlinear interaction of high-frequency linearly polarized electromagnetic (EM) waves and low-frequency electron plasma oscillations that are driven by the EM wave's ponderomotive force in a relativistic plasma with degenerate electrons. The relativistic degeneracy parameter is shown to modify the characteristics of EM solitons significantly. The unique features of the EM solitons are studied. The stability analysis of the EM solitons is also carried out by using the well-known Vakhitov-Kolokolov stability criterion. It is found that the EM solitons can be stable in weakly relativistic degenerate plasmas, whereas it may be unstable in the regime of ultra-relativistic degeneracy. The results may be useful for understanding the salient features of enhanced density fluctuations and the dynamics of X-ray pulses that may emanate from compact astrophysical objects, and also in the next-generation highly intense laser produced solid density compressed plasma experiments. (author)