Topological defects in multi-layered swarming bacteria

Victor Yashunsky, Daniel J.G. Pearce, Gil Ariel, Avraham Be’er

Research output: Contribution to journalArticlepeer-review


Topological defects, which are singular points in a director field, play a major role in shaping active systems. Here, we experimentally study topological defects and the flow patterns around them, that are formed during the highly rapid dynamics of swarming bacteria. The results are compared to the predictions of two-dimensional active nematics. We show that, even though some of the assumptions underlying the theory do not hold, the swarm dynamics is in agreement with two-dimensional nematic theory. In particular, we look into the multi-layered structure of the swarm, which is an important feature of real, natural colonies, and find a strong coupling between layers. Our results suggest that the defect-charge density is hyperuniform, i.e., that long range density-fluctuations are suppressed.

Original languageEnglish
JournalSoft Matter
StateAccepted/In press - 1 Jan 2024

ASJC Scopus subject areas

  • General Chemistry
  • Condensed Matter Physics

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