Parametric instabilities in relativistic plasma

Parametric instabilities in the relativistic plasma are considered. It is shown that in the electron relativistic plasma Tsub(e)>>msub(0e)c2) the electron mass oscillation in the external electrical field leads to the instability of Langmuir and low frequency aperiodic oscillations as well. In the case of the hot electron ion plasma with relativistic electron temperature the low frequency aperiodic and periodic oscillations are studied. The wave increments for all considered cases are obtained. (Auth.)