Figure 6
From: Subharmonic instability of a self-organized granular jet
Left panels: Horizontal coordinate x(t) of the center of gravity, indicating the position of the jet, for frequency f = 34 s−1 and amplitude A = (1.59, 1.81, 1.97, 2.16, 2.36) mm (from top to bottom).
The right panels show the corresponding absolute values of the Fourier-spectra, 
. For low and high values of amplitude, the horizontal position of the jet is almost invariant in the middle of the container. For intermediate values of amplitude, the Fourier spectra evidence a pronounced and stable subharmonic oscillation.
