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arXiv · 2510.00740

Superdiffusion and antidiffusion in an aligned active suspension

Lokrshi Prawar Dadhichi·Suvendra K. Sahoo·K. Vijay Kumar·Sriram Ramaswamy
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Abstract

We show theoretically that an imposed uniaxial anisotropy leads to new universality classes for the dynamics of active particles suspended in a viscous fluid. In the homogeneous state, their concentration relaxes superdiffusively, stirred by the long-ranged flows generated by its own fluctuations, as confirmed by our numerical simulations. Increasing activity leads to an anisotropic diffusive instability, and thus an original phase-separation mechanism, driven by the interplay of active stresses with a particle current proportional to the local curvature of the suspension velocity profile.

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Lokrshi Prawar Dadhichi, Suvendra K. Sahoo, K. Vijay Kumar, Sriram Ramaswamy. 2025-10-01. Superdiffusion and antidiffusion in an aligned active suspension. https://doi.org/10.1103/d61l-1tyh

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