We formulate a hydrodynamic theory of confluent epithelia: i.e. monolayers of epithelial cells adhering to each other without gaps. Taking advantage of recent progresses toward establishing a general hydrodynamic theory of p-atic liquid crystals, we demonstrate that collectively migrating epithelia feature both nematic (i.e. p = 2) and hexatic (i.e. p = 6) order, with the former being dominant at large and the latter at small length scales. Such a remarkable multiscale liquid crystal order leaves a distinct signature in the system's structure factor, which exhibits two different power law scaling regimes, reflecting both the hexagonal geometry of small cells clusters, as well as the uniaxial structure of the global cellular flow. We support these analytical predictions with two different cell-resolved models of epithelia - i.e. the self-propelled Voronoi model and the multiphase field model - and highlight how momentum dissipation and noise influence the range of fluctuations at small length scales, thereby affecting the degree of cooperativity between cells. Our construction provides a theoretical framework to conceptualize the recent observation of multiscale order in layers of Madin-Darby canine kidney cells and pave the way for further theoretical developments.

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Figure 2, 3 and 4 contain the numerical data used to generate the figures.

Article and author information

Author details

  1. Josep-Maria Armengol-Collado

    Instituut-Lorentz, Leiden University, Leiden, Netherlands
    Competing interests
    The authors declare that no competing interests exist.
  2. Livio Nicola Carenza

    Instituut-Lorentz, Leiden University, Leiden, Netherlands
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5996-331X
  3. Luca Giomi

    Instituut-Lorentz, Leiden University, Leiden, Netherlands
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7740-5960


European Research Council

  • Livio Nicola Carenza
  • Luca Giomi

Nederlandse Organisatie voor Wetenschappelijk Onderzoek

  • Josep-Maria Armengol-Collado

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Raymond E Goldstein, University of Cambridge, United Kingdom

Version history

  1. Preprint posted: February 1, 2022 (view preprint)
  2. Received: January 24, 2023
  3. Accepted: January 5, 2024
  4. Accepted Manuscript published: January 8, 2024 (version 1)
  5. Version of Record published: March 25, 2024 (version 2)


© 2024, Armengol-Collado et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.


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  1. Josep-Maria Armengol-Collado
  2. Livio Nicola Carenza
  3. Luca Giomi
Hydrodynamics and multiscale orderin confluent epithelia
eLife 13:e86400.

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