Dynamics of disclination loops in three-dimensional active nematics
In plain words
In three-dimensional gels driven by molecular motors, the chaotic flow is organized by closed loops of misalignment (defect loops) that appear, grow and vanish. What sets their birth rate, size and number is not understood.
Precise statement
Three-dimensional imaging of microtubule-kinesin active nematics (2020) showed that the chaotic state is dominated by disclination loops of zero net topological charge that nucleate, grow and self-annihilate. From active nematohydrodynamics, determine the loop nucleation mechanism, the loop size distribution and the scaling of loop density with activity and confinement, and compare with experiment.
What would settle it
A theory predicting loop density, size distribution and nucleation rate versus activity that agrees with 3D simulations and with confocal measurements on active nematic gels.