Excitation of Alfven waves and pulsar radio emission

Abstract

We analyze mechanisms of the excitation of Alfv\'{e}n wave in pulsar magnetospheres as a possible source of pulsar radio emission generation. We find that Cherenkov excitation of obliquely propagating Alfv\'{e}n waves is inefficient, while excitation at the anomalous cyclotron resonance by the particles from the primary beam and from the tail of the bulk distribution function may have a considerable growth rate. The cyclotron instability on Alfv\'{e}n waves occurs in the kinetic regime still not very closed to the star: $r \geq 50 R_{NS}$. We also discuss various mechanisms of conversion of Alfv\'{e}n waves into escaping radiation. Unfortunately, no decisive conclusion about the effectiveness of such conversion can be made.