Nonlinear propagation of intense electromagnetic waves in a hot electron–positron plasma

The creation and annihilation of relativistically hot electron–positron (EP) pair plasmas in the presence of intense electromagnetic (EM) waves, which are not in thermal equilibrium, are studied by formulating a new plasma particle distribution functions, which are valid for both relativistic temperatures and relativistic amplitudes of the EM waves. It is found that intense EM waves in a collisionless EP plasma damp via nonlinear Landau damping. Accounting for the latter, we have obtained relativistic kinetic nonlinear Schrödinger equation (NLSE) with local and non-local nonlinearities. The NLSE depicts nonlinear Landau damping rates for intense EM waves. The damping rates are examined for dense and tenuous pair plasmas. Furthermore, we have studied the modulational instabilities of intense EM waves in the presence of nonlinear Landau damping. Our results reveal a new class of the modulational instability that is triggered by the inverse Landau damping in a relativistically hot EP plasma. Finally, we discuss localization of intense EM waves due to relativistic electron and positron mass increase in a hot pair plasma.