Large-scale chaos and fluctuations in active nematics

Sandrine Ngo*, Anton Peshkov, Igor S. Aranson, Eric Bertin, Francesco Ginelli, Hugues Chate

*Corresponding author for this work

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We show that "dry" active nematics, e.g. collections of shaken elongated granular particles, exhibit large-scale spatiotemporal chaos made of interacting dense, ordered, band-like structures in a parameter region including the linear onset of nematic order. These results are obtained from the study of the relatively simple and well-known (deterministic) hydrodynamic equations describing these systems in a dilute limit, and of a self-propelled particle Vicsek-like model for this class of active matter. In this last case, revisiting the status of the strong fluctuations and long-range correlations now considered as landmarks of orientationally-ordered active phases, we show that the giant number fluctuations observed in the chaotic phase are a trivial consequence of density segregation. However anomalous density fluctuations are present in the homogeneous quasi-ordered nematic phase and characterized by a non-trivial scaling exponent.
Original languageEnglish
Article number038302
Number of pages6
JournalPhysical Review Letters
Issue number3
Publication statusPublished - 18 Jul 2014


  • giant number fluctuations
  • matter
  • microtubules
  • systems
  • fluids

Cite this

Ngo, S., Peshkov, A., Aranson, I. S., Bertin, E., Ginelli, F., & Chate, H. (2014). Large-scale chaos and fluctuations in active nematics. Physical Review Letters, 113(3), [038302].