Plasma instabilities of blazar-induced pair beams: a mini-review of current understanding
Martin Pohl
TeV blazars emit very high-energy gamma rays that interact with the extragalactic background light, producing relativistic electron–positron pair beams. These beams are expected to initiate electromagnetic cascades that give observable GeV-scale emission. Yet, for many blazars, this cascade component is absent in the observed spectra. One possible explanation attributes this suppression to weak intergalactic magnetic fields that deflect the pairs out of the line of sight. An alternative scenario