Active noise experienced by a passive particle trapped in an active bath

Area of Science:

• Statistical Mechanics
• Soft Matter Physics
• Active Matter Physics

Background:

• Particles in active baths experience complex noise dynamics.
• Understanding noise properties is crucial for active matter systems.

Purpose of the Study:

• To investigate the properties of active noise acting on a passive particle in an active bath.
• To compare simulation results with theoretical predictions for active noise.

Main Methods:

• Simulating an active bath using active Brownian particles.
• Representing the active bath abstractly using active colored noise in theoretical models.
• Extracting active noise by fitting theoretical predictions to simulation data.

Main Results:

• Active noise is dependent on the constraints of the passive tracer, unlike thermal noise.
• This constraint dependence stems from the influence of particle relaxation dynamics on persistent forces.
• Effective temperature increases with constraint strength, while average energies decrease.

Conclusions:

• Active noise properties are fundamentally different from thermal noise in constrained systems.
• The interplay between active collisions and relaxation dynamics governs the system's behavior.
• Findings offer insights into the dynamics of passive tracers in active environments.