Seminars

22 February 2024 (TBC)

Marco Mazza, Department of Mathematics, Loughborough University.
Topological Transitions in Active Spaghetti: from Motion to Structure

Abstract:
Filamentous cyanobacteria can show fascinating examples of nonequilibrium self-organization, which are not yet well understood from a physical perspective. We investigate the motility and collective organization of colonies of these simple multicellular lifeforms. As their area density increases, linear chains of cells gliding on a substrate show a transition from an isotropic distribution to bundles of filaments forming a network topology, known as 'reticulate pattern'. Based on our experimental observations of individual behaviour and pairwise interactions, we introduce a nonreciprocal model accounting for the filaments’ large aspect ratio, fluctuations in curvature, motility, and nematic interactions. This minimal model of active filaments recapitulates the observations and rationalizes the appearance of a characteristic length scale in the system, based on the Péclet number of the cyanobacteria filaments.

Ref.: Faluweki, Cammann, Mazza, Goehring, Phys. Rev. Lett. 131, 158303 (2023)

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17 April 2024 (TBC)

Vincent Caudrelier, Department of Mathematics, Leeds University.
TBC

Abstract:

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Archive 2023