A mesoscopic field theoretical approach for active systems

TL;DR

This paper presents a mesoscopic continuum model for active systems that integrates microscopic details with macroscopic behaviors, validated against agent-based models, and captures phenomena like collective motion and vortex formation.

Contribution

It introduces a novel mesoscopic modeling approach combining phase field crystal and Toner-Tu models for active systems with isotropic agents.

Findings

Reproduces microscopic model results for binary collisions and vortex formation.

Analyzes coarsening in active crystals and identifies giant number fluctuations.

Validates the continuum model against agent-based simulations.

Abstract

We introduce a mesocopic modeling approach for active systems. The continuum model allows to consider microscopic details as well as emerging macroscopic behavior and can be considered as a minimal continuum model to describe generic properties of active systems with isotropic agents. The model combines aspects from phase field crystal (PFC) models and Toner-Tu models. The results are validated by reproducing results obtained with corresponding agent-based microscopic models. We consider binary collisions, collective motion and vortex formation. For larger numbers of particles we analyze the coarsening process in active crystals and identify giant number fluctuation in the cluster formation process.