Regensburg 2022 – scientific programme
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BP: Fachverband Biologische Physik
BP 27: Statistical Physics of Biological Systems 2 (joint session BP/DY)
BP 27.3: Talk
Thursday, September 8, 2022, 15:30–15:45, H16
Random force yielding transition in spherical epithelia — Aboutaleb Amiri1, Charlie Duclut2, Frank Jülicher1, and •Marko Popović1 — 1Max Planck Institute for Physics of Complex Systems, Dresden — 2Université Paris Diderot, Paris
Developing biological tissues are often described as active viscoelastic fluids on long time-scales, due to fluidization by cell division and apoptosis. However, on shorter time-scales they can behave as amorphous solids with a finite yield stress [Mongera et al., Nature, 2018]. Under shear stress beyond the yield stress value amorphous solids begin to flow. This yielding transition is a dynamical phase transition characterized by a diverging correlation length and a set of critical exponents. Developing tissues are active matter systems whose constitutive cells can propel themselves by exerting traction forces. Recently, a remarkable correspondence has been proposed between uniformly sheared amorphous solids and dense self-propelled particle systems [Morse et al., PNAS, 2021] based on the identical scaling of non-linear properties of their energy landscapes. Here, we use a vertex model of epithelial tissues to study how randomly oriented traction forces fluidize a spherical epithelial tissue. In particular, we identify a sharp transition between quiescent and randomly flowing states separated by the critical value of the traction force magnitude, analogous to the yield stress. Moreover, we show that this transition is characterized by the same set of exponents as the classical yielding transition, and the corresponding scaling relations provide a non-trivial relation between cell geometry, cell rearrangement dynamics and tissue flow.