Response of active Brownian particles to shear flow

Area of Science:

• Soft Matter Physics
• Statistical Mechanics
• Active Matter

Background:

• Active Brownian particles (ABPs) are fundamental models for self-propelled entities.
• Understanding their collective behavior under external fields is crucial for applications.

Purpose of the Study:

• To derive and analyze the linear response of interacting ABPs to simple shear flow.
• To investigate how system properties like morphology and stress are affected by shear.

Main Methods:

• Utilized a path integral approach to derive linear response formulas.
• Employed correlation functions evaluated in the unperturbed system.
• Applied analytical and numerical methods for specific cases.

Main Results:

• Developed a general formula for the linear response of state observables to shear flow.
• Identified a simplified response formula for systems with xy-coordinate symmetry.
• Found that particle activity and alignment interactions enhance the shear response.

Conclusions:

• The study provides a theoretical framework for understanding shear flow effects on active matter systems.
• Enhanced particle activity and alignment interactions lead to a stronger response to shear.
• Results are applicable to confined interacting active particles, influencing their morphology and stress.