Lagrangian Manifestation of Anomalies in Active Turbulence

TL;DR

This paper investigates how active turbulence exhibits unique Lagrangian dynamics, revealing persistent Levy walk trajectories and super-diffusive behavior, which differ from inertial turbulence and may influence biological motility.

Contribution

It demonstrates the emergence of Levy walks and super-diffusive statistics in active turbulence, highlighting differences from inertial turbulence and suggesting broader universality of anomalous behaviors.

Findings

Active turbulence shows Levy walk trajectories.

Super-diffusive first passage distributions observed.

Active flows differ from inertial turbulence in pair dispersion.

Abstract

We show that Lagrangian measurements in active turbulence bear imprints of turbulent and anomalous streaky hydrodynamics leading to a self-selection of persistent trajectories - Levy walks - over diffusive ones. This emergent dynamical heterogeneity results in a super-diffusive first passage distribution which could lead to biologically advantageous motility. We then go beyond single-particle statistics to show that for the pair-dispersion problem as well, active flows are at odds with inertial turbulence. Our study, we believe, will readily inform experiments in establishing the extent of universality of anomalous behaviour across a variety of active flows.