PreprintarXiv licencearXiv
Active model B+ from run-and-tumble particles on a triangular lattice
Abstract
Active model B+ (AMB+) explains how motility-induced phase separation can be arrested by reverse Ostwald ripening, but its coefficients have not been derived from a microscopic lattice model that shows it. We provide an exact hydrodynamic description of a six-polarity lattice gas on a hexagonal geometry and employ a full gradient expansion with angular-harmonic elimination to rigorously derive AMB+ with every coefficient fixed by the Péclet number Pe. Near the critical point (3/4, 4), coarsening is ordinary; further away, field theory predicts reverse Ostwald ripening of vapor bubbles above Pe > 4 √3, and simulations show long-lived bubbly states.
Related
- Run-and-tumble particles in a harmonic external field: constructing the solution of the Fokker-Planck equation from the equations of motion
- Motility-Induced Phase Separation of Run-and-Tumble Particles under Local Stochastic Resetting
- Spatial density, first passage times, and entropy of run and tumble particles in a bistable potential
- Distribution Functions and Moments of Harmonically Trapped Inertial Run-and-Tumble Particles in a Shear-Thickening Medium
- Density and Current Fluctuations for Run-and-Tumble Particles With and Without Interactions
BibTeX
@misc{bhowmick2026active,
title = {{Active model B+ from run-and-tumble particles on a triangular lattice}},
author = {Abir Bhowmick and P. K. Mohanty},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.08296},
eprint = {2611.08296},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.08296},
}
RIS
TY - UNPB
TI - Active model B+ from run-and-tumble particles on a triangular lattice
AU - Abir Bhowmick
AU - P. K. Mohanty
PY - 2026
DA - 2026/11/05
PB - arXiv
DO - 10.48550/arxiv.2611.08296
UR - https://arxiv.org/abs/2611.08296
AB - Active model B+ (AMB+) explains how motility-induced phase separation can be arrested by reverse Ostwald ripening, but its coefficients have not been derived from a microscopic lattice model that shows it. We provide an exact hydrodynamic description of a six-polarity lattice gas on a hexagonal geometry and employ a full gradient expansion with angular-harmonic elimination to rigorously derive AMB+ with every coefficient fixed by the Péclet number Pe. Near the critical point (3/4, 4), coarsening is ordinary; further away, field theory predicts reverse Ostwald ripening of vapor bubbles above Pe > 4 √3, and simulations show long-lived bubbly states.
ER -