The statistical physics of active matter: from self-catalytic colloids to living cells

TL;DR

This paper introduces the phenomenology and analytical tools of active matter, highlighting how energy-driven interactions lead to complex, far-from-equilibrium behaviors in systems like colloids and living cells.

Contribution

It provides a concise overview of active matter phenomenology and presents models inspired by experiments to understand emergent behaviors.

Findings

Active systems exhibit new dynamics and phases due to energy consumption.

Interactions like steric, aligning, and shape-driven are key to emergent phenomena.

Models help unify understanding of synthetic and biological active matter.

Abstract

These lecture notes are designed to provide a brief introduction into the phenomenology of active matter and to present some of the analytical tools used to rationalize the emergent behavior of active systems. Such systems are made of interacting agents able to extract energy stored in the environment to produce sustained directed motion. The local conversion of energy into mechanical work drives the system far from equilibrium, yielding new dynamics and phases. The emerging phenomena can be classified depending on the symmetry of the active particles and on the type of microscopic interactions. We focus here on steric and aligning interactions, as well as interactions driven by shape changes. The models that we present are all inspired by experimental realizations of either synthetic, biomimetic or living systems. Based on minimal ingredients, they are meant to bring a simple and synthetic understanding of the complex phenomenology of active matter.