English

The Inertial Spin Model of flocking with position-dependent forces

Statistical Mechanics 2024-10-30 v3 Biological Physics Quantitative Methods

Abstract

We propose an extension to the ISM of flocking and swarming. The model has been introduced to explain certain dynamic features of swarming (second sound, a lower than expected dynamic critical exponent) while preserving the mechanism for onset of order provided by the Vicsek model. The ISM has only been formulated with an imitation (``ferromagnetic'') interaction between velocities. Here we show how to add position-dependent forces in the model, which allows to consider effects such as cohesion, excluded volume, confinement and perturbation with external position-dependent field, and thus study this model without periodic boundary conditions. We study numerically a single particle with an harmonic confining field and compare it to a Brownian harmonic oscillator and to a harmonically confined active Browinian particle, finding qualitatively different behavior in the three cases.

Keywords

Cite

@article{arxiv.2312.06368,
  title  = {The Inertial Spin Model of flocking with position-dependent forces},
  author = {Sebastián Carruitero and Alejo Costa Duran and Giulia Pisegna and Mauricio B. Sturla and Tomás S. Grigera},
  journal= {arXiv preprint arXiv:2312.06368},
  year   = {2024}
}

Comments

12 pages, 7 figures, published version

R2 v1 2026-06-28T13:47:05.405Z