Universality of temperature distribution in granular gas mixtures with a   steep particle size distribution
  Distribution of granular temperatures in granular gas mixtures is investigated analytically and numerically. We analyze space uniform systems in a homogeneous cooling state (HCS) and under a uniform heating with a mass-dependent heating rate $\Gamma_k\sim m_k^{\gamma}$. We demonstrate that for steep size distributions of particles the granular temperatures obey a universal power-law distribution, $T_k \sim m_k^{\alpha}$, where the exponent $\alpha$ does not depend on a particular form of the size distribution, the number of species and inelasticity of the grains. Moreover, $\alpha$ is a universal constant for a HCS and depends piecewise linearly on $\gamma$ for heated gases. The predictions of our scaling theory agree well with the numerical results. 
Anna Bodrova, Denis Levchenko and Nikolay Brilliantov
cond-mat.stat-mech