Dynamical scaling for probe particles in a driven fluid

TL;DR

This paper explores how probe particles in a one-dimensional driven fluid exhibit different dynamical scaling behaviors depending on the nature of the forces acting on them, revealing two universality classes with distinct exponents.

Contribution

It identifies and characterizes two universality classes for probe particle dynamics in driven fluids based on force correlations, linking them to different dynamical exponents.

Findings

Probe particles inherit fluid's dynamical exponent z=3/2 when force is driven by fluid fluctuations.

Uncorrelated force component leads to a dynamical exponent z=2.

Distinct universality classes depend on force correlation structure.

Abstract

We investigate two distinct universality classes for probe particles that move stochastically in a one-dimensional driven system. If the random force that drives the probe particles is fully generated by the current fluctuations of the driven fluid, such as when the probe particles are embedded in a ring, they inherit the dynamical exponent of the fluid, which generically is z=3/2. On the other hand, if the random force has a part that is temporally uncorrelated, the resulting motion can be described by a dynamical exponent z=2 as considered in previous work.