| 12/2023 Purely elastic turbulence in pressure-driven channel flows Martin Lellep et al. Solutions of long, flexible polymer molecules are complex fluids that simultaneously exhibit fluid-like and solid-like behaviour. When subjected to an external flow, dilute polymer solutions exhibit elastic turbulence – a unique, chaotic flow state absent in Newtonian fluids, like water. Unlike its Newtonian counterpart, elastic turbulence is caused by polymer molecules stretching and aligning in … |
| 11/2023 Diffusive evaporation dynamics in polymer solutions is ubiquitous Max Huisman et al. Recent theory and experiments have shown how the buildup of a high-concentration polymer layer at a one-dimensional solvent-air interface can lead to an evaporation rate that scales with time as $t^{-1/2}$ and that is insensitive to the ambient humidity. Using phase field modelling we show that this scaling law constitutes a naturally emerging robust regime, Diffusion-Limited Evaporation (DLE). Th … |
| 11/2023 Multifractality and statistical localization in highly heterogeneous random networks Diego Tapias et al. We consider highly heterogeneous random networks with symmetric interactions in the limit of high connectivity. A key feature of this system is that the spectral density of the corresponding ensemble exhibits a divergence within the bulk. We study the structure of the eigenvectors associated with this divergence and find that they are multifractal with the statistics of eigenvector elements matchi … |
| 11/2023 Mutual information as a measure of mixing efficiency in viscous fluids Yihong Shi et al. Because of the kinematic reversibility of the Stokes equation, fluid mixing at the microscale requires an interplay between advection and diffusion. Here we introduce mutual information between particle positions before and after mixing as a measure of mixing efficiency. We demonstrate its application in a Couette flow in an annulus and show that non-uniform rotation sequences can lead to more eff … |
| 11/2023 Dynamical theory of topological defects II: Universal aspects of defect motion Jacopo Romano et al. We study the dynamics of topological defects in continuum theories governed by a free energy minimization principle, building on our recently developed framework [Romano J, Mahault B and Golestanian R 2023 J. Stat. Mech.: Theory Exp. 083211]. We show how the equation of motion of point defects, domain walls, disclination lines and any other singularity can be understood with one unifying mathemati … |
| 11/2023 Hydrodynamic efficiency limit on a Marangoni surfer Abdallah Daddi-Moussa-Ider et al. A Marangoni surfer is an object embedded in a gas-liquid interface, propelled by gradients in surface tension. We derive an analytical theorem for the lower bound on the viscous dissipation by a Marangoni surfer in the limit of small Reynolds and capillary numbers. The minimum dissipation can be expressed with the reciprocal difference between drag coefficients of two passive bodies of the same sh … |
| 10/2023 Intercellular Friction and Motility Drive Orientational Order in Cell Monolayers Michael Chiang et al. Spatiotemporal patterns in multicellular systems are important to understanding tissue dynamics, for instance, during embryonic development and disease. Here, we use a multiphase field model to study numerically the behavior of a near-confluent monolayer of deformable cells with intercellular friction. Varying friction and cell motility drives a solid-liquid transition, and near the transition bou … |
| 10/2023 Entropy production and thermodynamic inference for stochastic microswimmers Michalis Chatzittofi et al. The question of characterization of the degree of non-equilibrium activity in active matter systems is studied in the context of a stochastic microswimmer model driven by a chemical cycle. The resulting dynamical properties and entropy production rate unravel a complex interplay between the chemical and the hydrodynamic degrees of freedom beyond linear response, which is not captured by convention … |
| 10/2023 Exploiting memory effects to detect the boundaries of biochemical subnetworks Moshir Harsh et al. Partial measurements of biochemical reaction networks are ubiquitous and limit our ability to reconstruct the topology of the reaction network and the strength of the interactions amongst both the observed and the unobserved molecular species. Here, we show how we can utilize noisy time series of such partially observed networks to determine which species of the observed part form its boundary, i. … |
| 10/2023 Topological phase locking in dissipatively-coupled noise-activated processes Michalis Chatzittofi et al. We study a minimal model of two non-identical noise-activated oscillators that interact with each other through a dissipative coupling. We find that the system exhibits a rich variety of dynamical behaviors, including a novel phase-locking phenomenon that we term topological phase locking (TPL). TPL is characterized by the emergence of a band of periodic orbits that form a torus knot in phase spac … |