ABSTRACT

We observe that interesting phenomena occur as Ac = 0 or Ac = -Ax. The system goes through a vertical bifurcation, where spinning modes go from stable supercritical (Fig. 2(d)) to unstable subcritical (Fig. 2(e)), or a standing mode from unstable subcritical (Fig. 2(b)) to stable supercritical (Fig. 2( c)). These transitions are observable, as they involve stable solutions.