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  • Open Access

Reduced density fluctuations via antialigning in active matter

Horst-Holger Boltz* and Thomas Ihle

  • *Contact author: horst-holger.boltz@uni-greifswald.de
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Phys. Rev. E 112, 065414 – Published 9 December, 2025

DOI: https://doi.org/10.1103/w9pf-3r76

Abstract

We highlight the importance of long-range correlations in active matter systems of self-propelling particles even in the absence of global order or steric interactions by demonstrating that long-range density fluctuations are reduced. We show this analytically for a one-dimensional lattice process employing a Poisson representation. Within this framework, we are able to derive the fluctuating hydrodynamics for the Poisson fields. The emergent imaginary noise indicates the non-Poissonian nature of the number fluctuations and manifests in a nontrivial structure factor S(k), which we are computing analytically. Numerically, we corroborate the relevance of these findings for off-lattice Vicsek-type models with antialigning interactions for which we observe apparent nonuniversal hyperuniformity, which we suggest to interpret as a reduction with integer power law to a finite value.

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Phys. Rev. E 112, 065414– Published 9 December, 2025
  • Received 20 September 2024
  • Accepted 14 November 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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