Revealing the Nonequilibrium Nature of a Granular Intruder: The Crucial Role of Non-Gaussian Behavior

Abstract

The characterization of the distance from equilibrium is a debated problem in particular in the treatment of experimental signals. If the signal is a 1-dimensional time-series, such a goal becomes challenging. A paradigmatic example is the angular diffusion of a rotator immersed in a vibro-fluidized granular gas. Here, we experimentally observe that the rotator's angular velocity exhibits significative differences with respect to an equilibrium process. Exploiting the presence of two relevant time-scales and non-Gaussian velocity increments, we quantify the breakdown of time-reversal asymmetry, which would vanish in the case of a 1D Gaussian process. We deduce a new model for the massive probe, with two linearly coupled variables, incorporating both Gaussian and Poissonian noise, the latter motivated by the rarefied collisions with the granular bath particles. Our model reproduces the experiment in a range of densities, from dilute to moderately dense, with a meaningful dependence of the parameters on the density. We believe the framework proposed here opens the way to a more consistent and meaningful treatment of out-of-equilibrium and dissipative systems.

arXiv comment5 pages, 4 figures

References in corpus (24)

• Stochastic thermodynamics, fluctuation theorems, and molecular machines
• Fluctuation-Dissipation: Response Theory in Statistical Physics
• Brownian yet non-Gaussian diffusion: from superstatistics to subordination of diffusing diffusivities
• "Diffusing diffusivity": A model for anomalous and "anomalous yet Brownian" diffusion
• Breakdown of Energy Equipartition in a 2D Binary Vibrated Granular Gas
• Observing Brownian motion in vibration-fluidized granular matter
• Generalized energy equipartition in harmonic oscillators driven by active baths
• Quantifying dissipation using fluctuating currents
• Improved bounds on entropy production in living systems
• Packets of Diffusing Particles Exhibit Universal Exponential Tails
• Loopy Lévy flights enhance tracer diffusion in active suspensions
• Minimal Model of Stochastic Athermal Systems: Origin of Non-Gaussian Noise
• Irreversible dynamics of a massive intruder in dense granular fluids
• Cages and anomalous diffusion in vibrated dense granular media
• Colossal Brownian yet non-Gaussian diffusion induced by nonequilibrium noise
• Nonequilibrium Brownian motion beyond the effective temperature
• Asymptotic derivation of Langevin-like equation with non-Gaussian noise and its analytical solution
• Inference in non-equilibrium systems from incomplete information: the case of linear systems and its pitfalls
• Dynamical collective memory in fluidized granular materials
• Langevin equations from experimental data: the case of rotational diffusion in granular media
• The Role of Data in Model Building and Prediction: A Survey Through Examples
• Slow time scales in a dense vibrofluidized granular material
• An Itinerant Oscillator model with cage inertia for mesorheological granular experiments
• Entropy production for velocity-dependent macroscopic forces: the problem of dissipation without fluctuations

Cited by in corpus (6)

• Brownian particle in a Poisson-shot-noise active bath: exact statistics, effective temperature, and inference
• Conceptual and practical approaches for investigating irreversible processes
• Discrete synaptic events induce global oscillations in balanced neural networks
• Statistical features of systems driven by non-Gaussian processes: theory & practice
• Synaptic shot-noise triggers fast and slow global oscillations in balanced neural networks
• Inference of Time-Reversal Asymmetry from Time Series in a Piezoelectric Energy Harvester