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arXiv · 2311.05377

Non-Gaussian displacements in active transport on a carpet of motile cells

Robert Großmann·Lara S. Bort·Ted Moldenhawer·Setareh Sharifi Panah·Ralf Metzler·Carsten Beta
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Abstract

We study the dynamics of micron-sized particles on a layer of motile cells. This cell carpet acts as an active bath that propels passive tracer particles via direct mechanical contact. The resulting nonequilibrium transport shows a crossover from superdiffusive to normal-diffusive dynamics. The particle displacement distribution is distinctly non-Gaussian even in the limit of long measurement times -- different from typically reported Fickian yet non-Gaussian transport, for which Gaussianity is restored beyond some system-specific correlation time. We obtain the distribution of diffusion coefficients from the experimental data and introduce a model for the displacement distribution that matches the experimentally observed non-Gaussian statistics and argue why similar transport properties are expected for many composite active matter systems.

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Robert Großmann, Lara S. Bort, Ted Moldenhawer, Setareh Sharifi Panah, Ralf Metzler, Carsten Beta. 2023-11-09. Non-Gaussian displacements in active transport on a carpet of motile cells. https://doi.org/10.1103/physrevlett.132.088301

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