Collision statistics in a dilute granular gas fluidized by vibrations in low gravity
Résumé
We report an experimental study of a dilute "gas" of inelastically colliding particles excited by vibrations in low gravity. We show that the mean collision frequency with a container wall does not scale linearly with the particle number N in the container, and that the probability density function of the impulse distribution has an exponential tail. The anomalous scaling with respect to N shows that the kinetic energy is not an extensive variable (i.e., the granular temperature is not intensive). This scaling is recovered with numerical simulations and is due to the dissipative nature of the collisions.