Published online by Cambridge University Press: 09 March 2009
Current driven electrostatic-wave- and electromagnetic-wave-produced resistivities do not occur in extragalactic jets for estimated values of the carried currents. Strong plasma double layers, however, may exist within self-maintained density cavities. The relativistic double-layer-emitted electron and ion beams drive plasma-wave resistivities in the low- and high-potential plasma adjacent to the double layers. The double-layeremitted electron beams may also emit polarized radio waves via a collectivebremsstrahlung process mediated by electrostatic two-stream instabilities.