A direct link between active matter and sheared granular systems

TL;DR

This paper establishes a theoretical connection between dense active matter and sheared amorphous solids, demonstrating their critical behavior equivalence through a mean-field model and numerical simulations, suggesting a universal framework for disordered materials.

Contribution

The authors develop a mean-field model linking active matter and sheared systems, validated by simulations, revealing their universal critical behavior in low dimensions.

Findings

Mean-field predictions match 2D simulations surprisingly well.

A new protocol, 'athermal quasi-static random displacement', effectively tests the model.

Identifies a class of perturbations interpolating between uncorrelated and correlated forces.

Abstract

The similarity in mechanical properties of dense active matter and sheared amorphous solids has been noted in recent years without a rigorous examination of the underlying mechanism. We develop a mean-field model that predicts that their critical behavior should be equivalent in infinite dimensions, up to a rescaling factor that depends on the correlation length of the applied field. We test these predictions in 2d using a new numerical protocol, termed `athermal quasi-static random displacement', and find that these mean-field predictions are surprisingly accurate in low dimensions. We identify a general class of perturbations that smoothly interpolate between the uncorrelated localized forces that occur in the high-persistence limit of dense active matter, and system-spanning correlated displacements that occur under applied shear. These results suggest a universal framework for predicting flow, deformation, and failure in active and sheared disordered materials.