Intermittency, fluctuations and maximal chaos in an emergent universal state of active turbulence

TL;DR

This paper investigates a hydrodynamic model of active suspensions, revealing a universal turbulent-like state characterized by spectral scaling and intermittent fluctuations, emerging beyond a critical activity level.

Contribution

It demonstrates the existence of a transition to a universal, chaotic state in active turbulence, supported by numerical and analytical evidence, linking maximal chaos to this transition.

Findings

Universal spectral scaling in active turbulence

Intermittent, non-Gaussian velocity fluctuations

Transition to maximal chaos at critical activity level

Abstract

A hydrodynamic model of active, low Reynolds number suspensions, shows the emergence of an asymptotic state with a universal spectral scaling and non-Gaussian (intermittent) fluctuations in the velocity field. Such states arise when these systems are pushed beyond a critical level of activity and show features akin to high Reynolds number, inertial turbulence. We provide compelling numerical and analytical evidence for the existence of such a transition at a critical value of activity and further show that the maximally chaotic states are tied to this transition.