The Relativistic Theory of Electro-Magneto-Ionic Waves

Abstract

The relativistic equations governing an ionized gas pervaded by static electric and magnetic fields and the corresponding equations for small perturbations, are derived. The equations for plane perturbations are then obtained and several important cases are developed in detail. Frequency bands in which growing wave-modes occur are also determined.By means of certain rules of transformation the theory is also used to study the plane waves which can occur in interpenetrating double streams of electrons. The results obtained are formally similar to those obtained for waves in an ionized gas.In the absence of static magnetic fields and with the effects of collisions neglected it is found that, in either an ionized gas or in interpenetrating double streams of electrons, certain waves propagated obliquely to the drift motions may both grow and possess Poynting fluxes; these fluxes are such that certain initial disturbances can lead to the escape of amplified electromagnetic energy from an ionized medium.The exchange of momentum and energy, between the streams of electrons and ions and the growing waves, is discussed by means of the momentum-energy tensors of the charged particles and of the electromagnetic field.The results of the relativistic theory are then used to discuss briefly the problem of the origin of cosmic noise and of "isolated bursts" and "outbursts" of solar noise. It is concluded that both theory and observation lend support to the hypothesis suggested previously that a notable part of cosmic noise and strong solar noise originates as electro-magneto-ionic waves in magnetized ionized regions. It would then follow that such regions occur in our Galaxy and in the Great Nebula in Andromeda. It is suggested that all "point sources" of cosmic noise be examined for at least transient traces of the Zeeman effect and an excess of elliptically polarized noise.