“…See, for instance, the left panel in Fig 3. For larger magnetic field strengths (case B5), we observe a stable behavior even in long term integration, as shown in the right panel of Fig 3. In the regime of strong magnetizations, in fact, the system can be well described by the force-free approximation. In this limit, our simulation results are in agreement with the findings of Istomin & Pariev (1994), (1996 who have shown that a jet with a longitudinal electric current remains stable with respect to helical as well as axially symmetric (pinch) modes. We believe that the induced stability owes to the stabilizing action of the electric field and, therefore, it has to be considered as a purely relativistic effect.…”