  The behaviour of a vertically vibrated granular bed is reminiscent of a
liquid in that it exhibits many phenomena such as convection and Faraday-like
surface waves. However, when the lateral dimensions of the bed are confined
such that a quasi-one-dimensional geometry is formed, the only phenomena that
remain are bouncing bed and the granular Leidenfrost effect. This permits the
observation of the granular Leidenfrost state for a wide range of energy
injection parameters, and more specifically allows for a thorough
characterisation of the low-frequency oscillation (LFO) that is present in this
state. In both experiments and particle simulations we determine the LFO
frequency from the power spectral density of the centre of mass signal of the
grains, varying the amplitude and frequency of the driving, the particle
diameter and the number of layers in the system. We thus find that (i) the LFO
frequency is inversely proportional to the fast inertial time scale and (ii)
decorrelates with a typical decay time proportional to the slow dissipative
time scale in the system. The latter is consistent with the view that the LFO
is driven by the inherent noise that is present in the granular Leidenfrost
state with a low number of particles.
