UNIQUENESS OF THE ALFVEN SINGULARITY IN A RELATIVISTIC PULSAR WIND

A splitting of the Alfven surface in an axisymmetric wind due to relat ivistic effects, suggested by Okamoto & Ardavan, does not occur. It is shown how spurious singularities can arise in the theory of relativis tic winds, and it is argued that only one singularity is genuine. This singularity is shown to correspond to a matching between the poloidal flow velocity and the poloidal component of the phase velocity of Alf ven waves, provided that the effect of the non-zero electric field and charge density is taken into account in deriving the dispersion relat ion of the Alfven waves.