Insertion space in repulsive active matter

Abstract

For equilibrium hard spheres, the statistical geometry of the insertion space, the room to accommodate another sphere, relates exactly to the equation of state. We begin to extend this idea to active matter, analyzing the insertion space for repulsive active particles in one and two dimensions using both on- and off-lattice models. In one dimension, we derive closed-form expressions for the mean insertion cavity size, cavity number, and total insertion volume, all in excellent agreement with simulations. Strikingly, activity increases the total insertion volume and tends to keep the insertion space more connected. We also find that insertion space metrics contain signatures of collective phase behaviors occurring at previously predicted packing fractions. Taken together, our work provides the first quantitative foundation for the statistical geometry of active matter.

5 pages main text, 4 main figures, 7 pages supplemental material

References in corpus (17)

• Motility-Induced Phase Separation
• How far from equilibrium is active matter?
• Pressure is not a state function for generic active fluids
• Towards a 'Thermodynamics' of Active Matter
• Thermodynamic phases in two-dimensional active matter
• Time-(ir)reversibility in active matter: from micro to macro
• Autonomous engines driven by active matter: Energetics and design principles
• Microscopic versus macroscopic approaches to non-equilibrium systems
• Colloidal Hard Spheres: Triumphs, Challenges and Mysteries
• Universal Properties of a Run-and-Tumble Particle in Arbitrary Dimension
• Active matter under control: Insights from response theory
• Active hard-spheres in infinitely many dimensions
• Hard core run and tumble particles on a one dimensional lattice
• Active matter, microreversibility, and thermodynamics
• Kinetic temperature and pressure of an active Tonks gas
• An equation of state for active matter
• Optimal run-and-tumble in slit-like confinement