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Updated: Aug 20, 2025

The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Passive objects in confined active fluids: A localization transition
Ydan Ben Dor1, Yariv Kafri1, Mehran Kardar2
1Department of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Abstract:
We study how walls confining active fluids interact with asymmetric passive objects placed in their bulk. We show that the objects experience nonconservative long-ranged forces mediated by the active bath. To leading order, these forces can be computed using a generalized image theorem. The walls repel asymmetric objects, irrespective of their microscopic properties or their orientations. For circular cavities, we demonstrate how this may lead to the localization of asymmetric objects in the center of the cavity, something impossible for symmetric ones.
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