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DY: Fachverband Dynamik und Statistische Physik

DY 59: Brownian Motion and Anomalous Diffusion

DY 59.4: Talk

Friday, March 22, 2024, 10:15–10:30, BH-N 334

Run-and-trap motility of self-propelled particles — •Agniva Datta, Sönke Beier, Veronika Pfeifer, Carsten Beta, and Robert Großmann — University of Potsdam, Potsdam, Germany

In many experimental manifestations of active matter, self-propelled particles have been observed to exhibit dynamic transitions between different states of motility that are characterized by various features such as velocity and rotational diffusion coefficients as well as their duration. These multi-state motility behaviors often result in non-Gaussian statistics, anomalous diffusion and ergodicity breaking. We introduce a comprehensive dynamical motility model for self-propelled particles whose active run motility is intermittently interrupted by a trap state as it is observed, for example, for active motion in disordered media. Thereby, we provide a unified framework to study Lévy walks, classical continuous-time random walks and active diffusion models such as active Brownian motion, run-and-tumble or run-and-reverse. We analytically derive expressions for essential quantities, including mean-squared displacements and diffusion coefficients, crucial for understanding the intricacies of these processes. We illustrate the applicability of our model to experimental data using the example of soil bacteria spreading in agar.

Keywords: active motion in disordered media; anomalous diffusion; physics of living systems; bacterial motility