Collective behavior based on agent-environment interactions

TL;DR

This paper models active particles interacting with a dynamic environment, revealing emergent collective behaviors like waves and clusters driven by environmental feedback and resource dynamics, without direct agent interactions.

Contribution

It introduces a novel model combining chemotaxis, resource regrowth, and population dynamics to explain complex collective patterns emerging from environment-agent interactions.

Findings

Identified phases of collective organization including disordered, wave, and cluster states.

Demonstrated spontaneous symmetry breaking and density waves driven by environmental feedback.

Bridged active matter physics and movement ecology through environmental coupling.

Abstract

We present a model of active particles interacting through a dynamic, heterogeneous environment, leading to emergent collective behaviors without direct agent-to-agent communication. Expanding the resource-dependent framework introduced in Briozzo et al., 2025, arXiv:2512.08762, agents perform a persistent random walk combined with chemotaxis, directing toward nutrient-rich patches, whose resources are generated by logistic regrowth. We identify distinct phases of collective organization, ranging from disordered gas-like states to polar traveling waves and nematic independent clusters, depending on the interplay between chemotactic sensitivity and angular noise. The system exhibits spontaneous symmetry breaking and density waves driven purely by the coupling between population dynamics (birth-death processes) and environmental feedback. Our results bridge active matter physics and movement ecology, demonstrating that complex spatiotemporal patterns can arise without direct interaction between agents, but solely from the maximization of resource intake in a reactive environment.