Rotationally driven gas of inelastic rough spheres

We study a two-dimensional gas of inelastic rough spheres, driven on the rotational degrees of freedom. Numerical simulations are compared to mean-field (MF) predictions with surprisingly good agreement for strong coupling of rotational and translational degrees of freedom -- even for very strong dissipation in the translational degrees. Although the system is spatially homogeneous, the rotational velocity distribution is essentially Maxwellian. Surprisingly, the distribution of tangential velocities is strongly deviating from a Maxwellian. An interpretation of these results is proposed, as well as a setup for an experiment.