Violation of the Einstein relation in Granular Fluids: the role of correlations

Abstract

We study the linear response in different models of driven granular gases. In some situations, even if the the velocity statistics can be strongly non-Gaussian, we do not observe appreciable violations of the Einstein formula for diffusion versus mobility. The situation changes when strong correlations between velocities and density are present: in this case, although a form of fluctuation-dissipation relation holds, the differential velocity response of a particle and its velocity self-correlation are no more proportional. This happens at high densities and strong inelasticities, but still in the fluid-like (and ergodic) regime.

arXiv comment18 pages, 6 figures, submitted for publication

References in corpus (21)

• Clustering, Order, and Collapse in a Driven Granular Monolayer
• Particle dynamics in sheared granular matter
• Restoring a fluctuation-dissipation theorem in a nonequilibrium steady state
• Clustering and Non-Gaussian Behavior in Granular Matter
• Randomly Driven Granular Fluids: large scale structure
• Randomly Driven Granular Fluids: collisional statistics and short scale structure
• A kinetic approach to granular gases
• Forcing and Velocity Correlations in a Vibrated Granular Monolayer
• Influence of correlations on the velocity statistics of scalar granular gases
• Transport Coefficients for Granular Media from Molecular Dynamics Simulations
• The Inelastic Maxwell Model
• Transport coefficients of a heated granular gas
• Fluctuation-Dissipation relations in Driven Granular Gases
• Fluctuations of internal energy flow in a vibrated granular gas
• Temperature probes in binary granular gases
• Fluid-like behavior of a one-dimensional granular gas
• Green-Kubo Expressions for a Granular Gas
• Fluctuations of power injection in randomly driven granular gases
• On the Einstein relation in a heated granular gas
• What is the temperature of a granular medium?
• Fluctuation-dissipation relations in driven dissipative systems

Cited by in corpus (32)

• Temperature in and out of equilibrium: a review of concepts, tools and attempts
• Statistical mechanics of a chiral active fluid
• Irreversible effects of memory
• Irreversible dynamics of a massive intruder in dense granular fluids
• Nonequilibrium Linear Response for Markov Dynamics, II: Inertial Dynamics
• The fluctuation-dissipation relation: how does one compare correlation functions and responses?
• Kovacs-like memory effect in driven granular gases
• Structure factors in granular experiments with homogeneous fluidization
• Granular Brownian motion
• Fluctuating hydrodynamics and correlation lengths in a driven granular fluid
• Fluctuation-Dissipation relation in sub-diffusive systems: the case of granular single-file
• Nonequilibrium Brownian motion beyond the effective temperature
• Fluctuating hydrodynamics for dilute granular gases
• Dynamical collective memory in fluidized granular materials
• Memory effect in uniformly heated granular gases
• On anomalous diffusion and the out of equilibrium response function in one-dimensional models
• Frequency-dependent fluctuation-dissipation relations in granular gases
• Fast decay of the velocity autocorrelation function in dense shear flow of inelastic hard spheres
• Breakdown of fluctuation-dissipation relations in granular gases
• Fluctuating Navier-Stokes equations for inelastic hard spheres or disks
• Stability of freely cooling granular mixtures at moderate densities
• The Many Faces of Fluctuation-Dissipation Relations Out of Equilibrium
• Volume fluctuations and compressibility of a vibrated granular gas
• Tagged active particle: probability distribution in a slowly varying external potential is determined by effective temperature obtained from the Einstein relation
• Fluctuating hydrodynamics for dilute granular gases: a Monte Carlo study
• Diffusion in Agitated Frictional Granular Matter Near the Jamming Transition
• Rheological effects in the linear response and spontaneous fluctuations of a sheared granular gas
• A note on the violation of the Einstein relation in a driven moderately dense granular gas
• Fluctuation-Dissipation Relations for Motions of Center of Mass in Driven Granular Fluids under Gravity
• Mobility and diffusion of intruders in granular suspensions. Einstein relation
• Fluctuations in granular gases
• Internal energy fluctuations of a granular gas under steady uniform shear flow