Scaling and universality of critical fluctuations in granular gases

TL;DR

This study uses molecular dynamics simulations to analyze energy fluctuations in granular gases near clustering instability, revealing universal power-law divergence and distribution collapse similar to other systems, with sign differences.

Contribution

It demonstrates the universality of fluctuation behavior in granular gases and identifies a common distribution form with other systems, highlighting critical phenomena.

Findings

Energy fluctuations diverge as a power law near instability

Fluctuation distributions collapse onto a universal curve

Sign of fluctuations differs from equilibrium systems

Abstract

The global energy fluctuations of a low density gas granular gas in the homogeneous cooling state near its clustering instability are studied by means of molecular dynamics simulations. The relative dispersion of the fluctuations is shown to exhibit a power-law divergent behavior. Moreover, the probability distribution of the fluctuations presents data collapse as the system approaches the instability, for different values of the inelasticity. The function describing the collapse turns out to be the same as the one found in several molecular equilibrium and non-equilibrium systems, except for the change in the sign of the fluctuations.