Intermittency Signatures in the Deformation of a Passive Droplet in Active Turbulence

Abstract

We use fully resolved nematohydrodynamic simulations to study deformation statistics of a passive nematic droplet in two-dimensional extensile active-nematic turbulence. We find that the droplet aspect ratio serves as a scalar probe of the active bath. Its increments show heavy-tailed distributions with dependence on the time lag, scale-free burst statistics and multiscaling structure functions which establish temporal intermittency. While the mean deformation increases with activity, normalized intermittency is strongest at lower activity. This suggests slower and more coherent bath forcing. When compared with translational and forcing-side fluctuations, it reveals a hierarchy of intermittency: shape is more weakly intermittent than translation and active-stress fluctuations, consistent with filtering by interfacial restoring forces. Power spectra show an extended near-$1/ω$ regime for the maximal normal interface velocity, distinct from the steeper, approximately $1/ω^{2}$ spectrum of the interfacial active stress. Soft inclusions thus reveal how interfacial restoring forces convert active forcing into bursty, scale-rich deformation dynamics.