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Updated: Jun 4, 2025

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Thermodynamic constraints and exact scaling exponents of flocking matter
Andrea Amoretti1, Daniel K Brattan1, Luca Martinoia1
1Dipartimento di Fisica, <a href="https://ror.org/0107c5v14">Università di Genova</a>, via Dodecaneso 33, I-16146 Genova, Italy and <a href="https://ror.org/02v89pq06">I.N.F.N.-Sezione di Genova</a>, via Dodecaneso 33, I-16146 Genova, Italy.
Abstract:
We use advances in the formalism of boost agnostic passive fluids to constrain transport in polar active fluids, which are subsequently described by the Toner-Tu equations. Acknowledging that the system fundamentally breaks boost symmetry, we compel what were previously entirely phenomenological parameters in the Toner-Tu model to satisfy precise relationships among themselves. Consequently, we propose a thermodynamic argument to determine the scalings of the transport coefficients under dynamical renormalization group flow given that the scaling of the noise correlator is exact, as has been supported numerically. These scalings perfectly agree with the results of recent state-of-the-art numerical simulation and experiments.
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