Amir Shee, Northwestern University

Emerging States in Dense Systems of Chiral Active Particles

Across scales, from molecules to tissues, dense biological systems can exhibit collective dynamics driven by activity and elastic interactions, including flocking transitions and long-range spatiotemporal order. In this work, we consider densely packed systems of active Brownian particles with intrinsic individual chirality from a theoretical perspective, showing that these can lead to the emergence of a variety of states, including collective rotating mesoscopic order. Using dual analytical approaches—one based on normal modes and the other on continuum elasticity—this study provides a comprehensive understanding of the states that can be observed in the systems, matching very well our numerical simulations. Our findings suggest that the collective rotating states that we identify may generically appear in natural and artificial dense chiral active systems.