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arXiv · 2302.14756

Compact expansion of a repulsive suspension

Matan Yah Ben Zion·Naomi Oppenheimer
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Abstract

Short-range repulsion governs the dynamics of matter from atoms to animals. Using theory, simulations, and experiments, we find that an ensemble of repulsive particles spreads compactly with a sharp boundary, in contrast to the diffusive spreading of Brownian particles. Starting from the pair interactions, at high densities, the many-body dynamics follow non-linear diffusion with a self-similar expansion, growing as $t^{1/4}$; At longer times, thermal motion dominates with the classic $t^{1/2}$ expansion. A logarithmic growth controlled by nearest-neighbor interactions connects the two self-similar regimes.

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Matan Yah Ben Zion, Naomi Oppenheimer. 2023-02-28. Compact expansion of a repulsive suspension. https://arxiv.org/abs/2302.14756

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