Colloquium

Relativistic-Amplitude electromagnetic waves –

Beating the “magnetic” barrier

 Swadesh Mahajan, Research Professor, University of Texas at Austin

 Abstract: The dispersion characteristics of an arbitrary amplitude circularly polarized electromagnetic wave, propagating in a highly (thermally and kinematically) relativistic plasma, are shown to approach those of a linear wave in an unmagnetized, non-relativistic plasma. Further aided by high relativistic temperatures, the cut-off frequency tends to become negligibly small; waves with frequencies well below the nominal plasma and the cyclotron frequencies find the plasma to be essentially transparent. This spectacular relativistic phenomenon will greatly advance our ability to understand and model the dynamics of a large class of astrophysical and laser-produced high energy density systems.