Boundary layers, transport and universal distribution in boundary driven active systems

Dolai P, Das A (2025)


Publication Type: Journal article

Publication year: 2025

Journal

Book Volume: 19

Article Number: 088

Journal Issue: 4

DOI: 10.21468/SciPostPhys.19.4.088

Abstract

We discuss analytical results for a run-and-tumble particle (RTP) in one dimension in presence of boundary reservoirs. It exhibits “kinetic boundary layers”, nonmonotonous distribution, current without density gradient, diffusion facilitated current reversal and optimisation on tuning dynamical parameters, and a new transport effect in the steady state. The spatial and internal degrees of freedom together possess a symmetry, using which we find the eigenspectrum for large systems. The eigenvalues are arranged in two bands which can mix in certain conditions resulting in a crossover in the relaxation. The late time distribution for large systems is obtained analytically; it retains a strong and often dominant “active” contribution in the bulk rendering an effective passive-like description inadequate. A nontrivial “Milne length” also emerges in the dynamics. Finally, a novel universality is proposed in the absorbing boundary problem for dynamics with short-range colored noise. Active processes driven by active reservoirs may thus provide a common physical ground for diverse and new nonequilibrium phenomena.

Involved external institutions

How to cite

APA:

Dolai, P., & Das, A. (2025). Boundary layers, transport and universal distribution in boundary driven active systems. SciPost Physics, 19(4). https://doi.org/10.21468/SciPostPhys.19.4.088

MLA:

Dolai, Pritha, and Arghya Das. "Boundary layers, transport and universal distribution in boundary driven active systems." SciPost Physics 19.4 (2025).

BibTeX: Download