Aristotelian Electrodynamics solves the Pulsar: Lower Efficiency of Strong Pulsars

In Aristotelian Electrodynamics (AE), due to radiation over-damping, the velocity rather than the acceleration of a charge is determined by the local electromagnetic field. Treating electrons and positrons separately, AE seems to give a faithful description of the flow of charges in a pulsar magnetosphere. AE might allow to calculate the pulsar emission in full detail, at all energies except the radio. But AE is not a full theory -- the plasma production processes must be added. Here we show that the pulsar magnetosphere and the resulting emission are sensitive to the plasma production rate near the light cylinder. In strong pulsars (high production rate, due to photon-photon collisions), the number of field lines closing beyond the light cylinder decreases. This reduces both the pulsar efficiency (the ratio of the pulsed bolometric luminosity to the spin-down power) and the characteristic photon energy, in overall agreement with the Fermi data. For weak pulsars (low production rate), our numerical implementation of AE works stably and seems to be ready to calculate the lightcurves and spectra. But for strong pulsars, the code (included) needs improvement or better understanding.