Dynamical Spreading Under Power Law Potential

Fuente: arXiv
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Main Authors: Fanto, Ido, Oppenheimer, Naomi
Format: Preprint
Published: 2025
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author Fanto, Ido
Oppenheimer, Naomi
author_facet Fanto, Ido
Oppenheimer, Naomi
contents We examine the dynamic spreading of a dense overdamped suspension of particles under power law repulsive potentials, often called Riesz gases. That is, potentials that decay with distance as 1/r^k where k\in (-2,\infty]. Depending on the value of k relative to the system's spatial dimension $D$, the potentials are categorized as short-ranged for k > D, and long-ranged when $k \leq D$. Such systems naturally occur in contexts involving particle suspensions, granular media, and charged systems, where interactions can be influenced by physical fields that decrease over distance. Our analytical findings reveal that the particles spread in a self-similar form, with the radius growing with time as t^1/(k+2). The theoretical predictions derived for a general dimension D, are verified by numerical simulations involving thousands of particles in free space, in both one and two dimensions. Furthermore, the simulations not only confirm our analytical results but also reveal a rich diversity of behaviors depending on the value of k. We demonstrate that the density profiles differ significantly depending on whether k is larger than, smaller than, or equal to D-2, where D is the dimension. For k>D-2 the density is centered in the middle and we also notice a Wigner lattice emerging as a result of the repulsive interactions, for k = D-2, density is uniform and for k<D-2, density is centered at the edges. This new classification indicates that the long/short-range classification is insufficient for predicting the density profile of the suspension. When k<D-2, we observed an interesting phenomenon when two or more suspensions are placed near each other: a particle-free zone is formed where the two populations meet, resembling structures of bubbles.
format Preprint
id arxiv_https___arxiv_org_abs_2501_05846
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Dynamical Spreading Under Power Law Potential
Fanto, Ido
Oppenheimer, Naomi
Soft Condensed Matter
Mathematical Physics
We examine the dynamic spreading of a dense overdamped suspension of particles under power law repulsive potentials, often called Riesz gases. That is, potentials that decay with distance as 1/r^k where k\in (-2,\infty]. Depending on the value of k relative to the system's spatial dimension $D$, the potentials are categorized as short-ranged for k > D, and long-ranged when $k \leq D$. Such systems naturally occur in contexts involving particle suspensions, granular media, and charged systems, where interactions can be influenced by physical fields that decrease over distance. Our analytical findings reveal that the particles spread in a self-similar form, with the radius growing with time as t^1/(k+2). The theoretical predictions derived for a general dimension D, are verified by numerical simulations involving thousands of particles in free space, in both one and two dimensions. Furthermore, the simulations not only confirm our analytical results but also reveal a rich diversity of behaviors depending on the value of k. We demonstrate that the density profiles differ significantly depending on whether k is larger than, smaller than, or equal to D-2, where D is the dimension. For k>D-2 the density is centered in the middle and we also notice a Wigner lattice emerging as a result of the repulsive interactions, for k = D-2, density is uniform and for k<D-2, density is centered at the edges. This new classification indicates that the long/short-range classification is insufficient for predicting the density profile of the suspension. When k<D-2, we observed an interesting phenomenon when two or more suspensions are placed near each other: a particle-free zone is formed where the two populations meet, resembling structures of bubbles.
title Dynamical Spreading Under Power Law Potential
topic Soft Condensed Matter
Mathematical Physics
url https://arxiv.org/abs/2501.05846