Related Experiment Video
Updated: Jul 19, 2025

Forming, Confining, and Observing Microtubule-Based Active Nematics
Published on: January 13, 2023
Equation of state for active matter
Samuel Cameron1, Majid Mosayebi1, Rachel Bennett1
1School of Mathematics, Fry Building, University of Bristol, Bristol BS8 1UG, United Kingdom.
None:
We characterize the steady states of a suspension of two-dimensional active Brownian particles (ABPs). By approximating the first-order correction to the steady-state probability distribution to lowest order in Peclet number, we show that macroscopic quantities can be calculated in analogous way to equilibrium systems using this probability distribution. We then derive expressions for the macroscopic pressure and position-orientation correlation functions. We check our results by direct comparison with extensive numerical simulations. A key finding is the importance of many-body effective interactions even at very low densities.
Related Concept Videos
Equation of State
Equation of Motion: Center of Mass
Internal forces between any pair of particles manifest as collinear pairs of equal magnitude but opposite directions,...
Equations of Equilibrium in Three Dimensions
According to the vector equations of equilibrium, the vector sum of all the external forces acting on a body must...
States of Matter
Scientists have discovered a fourth state of matter, plasma, that occurs naturally in the interiors...
Equilibrium Conditions for a Particle
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
Dynamic Equilibrium

