Characterizing rare fluctuations in soft particulate flows

Abstract

Soft particulate media include a wide range of systems involving athermal dissipative particles both in non-living and biological materials. Characterization of flows of particulate media is of great practical and theoretical importance. A fascinating feature of these systems is the existence of a critical rigidity transition in the dense regime dominated by highly intermittent fluctuations that severely affects the flow properties. Here, we unveil the underlying mechanisms of rare fluctuations in soft particulate flows. We find that rare fluctuations have different origins above and below the critical jamming density and become suppressed near the jamming transition. We then conjecture a time-independent local fluctuation relation, which we verify numerically, and that gives rise to an effective temperature. We discuss similarities and differences between our proposed effective temperature with the conventional kinetic temperature in the system by means of a universal scaling collapse.

7 pages, 4 figures, to appear in Nature Communications (2017)

References in corpus (3)

• Fluctuation-Dissipation: Response Theory in Statistical Physics
• Scaling properties of granular rheology near the jamming transition
• Critical Scaling of Bagnold Rheology at the Jamming Transition of Frictionless Two Dimensional Disks

Cited by in corpus (5)

• Unified Modeling and Experimental Realization of Electrical and Thermal Percolation in Polymer Composites
• A topological fluctuation theorem
• Stochastic thermodynamics of a confined colloidal suspension under shear flow
• Power fluctuations in sheared amorphous materials: A minimal model
• Dynamic susceptibilities in dense soft athermal spheres under a finite-rate shear