Equilibrium mappings in polar-isotropic confined active particles

Yaouen Fily; Aparna Baskaran; Michael F. Hagan

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arXiv · 1612.08719

Equilibrium mappings in polar-isotropic confined active particles

Yaouen Fily·Aparna Baskaran·Michael F. Hagan

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Abstract

Despite their fundamentally non-equilibrium nature, the individual and collective behavior of active systems with polar propulsion and isotropic interactions (polar-isotropic active systems) are remarkably well captured by equilibrium mapping techniques. Here we examine two signatures of equilibrium systems -- the existence of a local free energy function and the independence of the coarse- grained behavior on the details of the microscopic dynamics -- in polar-isotropic active particles confined by hard walls of arbitrary geometry at the one-particle level. We find that boundaries that possess concave regions make the density profile strongly dynamics-dependent and give it a nonlocal dependence on the geometry of the confining box. This in turn constrains the scope of equilibrium mapping techniques in polar-isotropic active systems.

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Yaouen Fily, Aparna Baskaran, Michael F. Hagan. 2016-12-27. Equilibrium mappings in polar-isotropic confined active particles. https://arxiv.org/abs/1612.08719

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