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BP: Fachverband Biologische Physik
BP 24: Active Matter IV (joint session DY/BP/CPP)
BP 24.1: Vortrag
Mittwoch, 18. März 2020, 10:00–10:15, ZEU 160
Quantitative Assessment of the Toner and Tu Theory of Polar Flocks — •Benoît Mahault1,2, Francesco Ginelli3,4, and Hugues Chaté1,5,6 — 1Service de Physique de l'Etat Condensé, CEA, CNRS, Université Paris-Saclay, CEA-Saclay, France — 2Max Planck Institute for Dynamics and Self-Organization (MPIDS), Germany — 3University of Aberdeen, United Kingdom — 4Università degli Studi dell'Insubria, Italy — 5Beijing Computational Science Research Center, China — 6LPTMC, CNRS UMR 7600, Université Pierre et Marie Curie, France
We present a quantitative assessment of the Toner and Tu theory describing the universal scaling of space-time correlations functions in polar phases of dry active matter. Using large-scale simulations of the Vicsek model in two and three dimensions, we find the overall phenomenology and generic algebraic scaling predicted by Toner and Tu, but our data on density correlations reveal some qualitative discrepancies. The values of the associated scaling exponents we estimate differ significantly from those conjectured in 1995. In particular, we identify a large crossover scale beyond which flocks are only weakly anisotropic. We discuss the meaning and consequences of these results.