Related Experiment Video
Updated: Jun 3, 2025

Forming, Confining, and Observing Microtubule-Based Active Nematics
Published on: January 13, 2023
Kinetic Theory of Self-Propelled Particles with Nematic Alignment
Horst-Holger Boltz1, Benjamin Kohler1, Thomas Ihle1
1Institute for Physics, University of Greifswald, 17489 Greifswald, Germany.
Abstract:
We present the results from kinetic theory for a system of self-propelled particles with alignment interactions of higher-order symmetry, particularly nematic ones. To this end, we use the Landau equation approach, a systematic approximation to the BBGKY hierarchy for small effective couplings. Our calculations are presented in a pedagogical way with the explicit goal of serving as a tutorial from a physicists' perspective into applying kinetic theory ideas beyond mean-field to active matter systems with essentially no prerequisites and yield predictions without free parameters that are in quantitative agreement with direct agent-based simulations.
More Related Videos
Related Concept Videos
Equations of Motion: Rectangular Coordinates and Cylindrical Coordinates
When a particle moves relative to an inertial frame, the equations of motion can be expressed using rectangular components. If the motion is confined to the x-y plane, the equations having the x and y coordinates only can be used to simplify the mathematical representation.
However, when particles...
Principle of Linear Impulse and Momentum for a System of Particles
Notably, internal forces between particles, occurring in equal and opposite collinear pairs, cancel out and are not part of the equation of motion. This exclusion simplifies the...
First Law: Particles in Two-dimensional Equilibrium
Newton's first law tells us about...
First Law: Particles in One-dimensional Equilibrium
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...
Equation of Motion: Center of Mass
Internal forces between any pair of particles manifest as collinear pairs of equal magnitude but opposite directions,...

