Large-scale structure from superdiffusion in a driven dissipative system

TL;DR

This paper demonstrates through simulations that superdiffusive transport in a driven granular gas causes giant density fluctuations due to velocity-dependent dissipation, revealing a causal link between structure and dynamics in non-equilibrium systems.

Contribution

It uncovers a direct causal relationship between superdiffusion and density fluctuations driven by velocity-dependent dissipation in a non-equilibrium granular system.

Findings

Superdiffusive transport correlates with giant density fluctuations.

Velocity-dependent dissipation causes persistent directional motion.

A scaling argument supports the causal link between structure and transport.

Abstract

A system far from equilibrium is characterized by unconventional many-body dynamical effects, which can lead to anomalous density fluctuations and mass transport. Interestingly, these structural and dynamic features often emerge simultaneously in driven dissipative systems. Here we seek an origin of their co-existence by numerical simulations of a two-dimensional driven granular gas. We reveal a causal link between superdiffusive transport and giant density fluctuations. The kinetic dissipation upon particle collisions depends on the relative velocity of colliding particles, and is responsible for the self-generated large-scale persistent directional motion of particles that underlies the link between structure and transport. This scenario is supported by a simple scaling argument.