Nv. Brilliantov et T. Poschel, Deviation from Maxwell distribution in granular gases with constant restitution coefficient, PHYS REV E, 61(3), 2000, pp. 2809-2812
We analyze the velocity distribution function of force-free granular gases
in the regime of homogeneous cooling when deviations from the Maxwellian di
stribution may be accounted only by the leading term in the Sonine polynomi
al expansion, quantified by the second coefficient a,. We go beyond the lin
ear approximation for a(2) and find three different values (three roots) fo
r this coefficient which correspond to a scaling solution of the Boltzmann
equation. The stability analysis performed showed, however, that among thes
e three roots only one corresponds to a stable scaling solution. This is ve
ry close to at, obtained in previous studies in a linear with respect to ae
approximation.