Institut Charles Sadron Event

Horaire: 14h15 Abstract: Microscopic interactions among the material constituents shape macroscopic patterns. Recent observations have shown that monolayers of cells exhibit a rich repertoire of mechanical patterns, ranging from chaotic cell flows to propagating waves. However, our understanding of how do cell parameters affect the underlying mechanisms of pattern formation remains still in its infancy. Here, I will present a hydrodynamical description of an active fluid with polar symmetry for understanding the 2D collective dynamics of cell monolayers. At a critical level of activity, the ordered polar phase can undergo an oscillatory periodic instability, leading to nonlinear waves. Akin to cell monolayers, our system can sustain elastic-like waves with a phase lag between stresses and strain-rate oscillations that depends on material parameters and substrate interactions. Near the instability point, we found that the long-ranged spatiotemporal dynamics admits a reduced description in terms of a Complex Ginzburg Landau amplitude equation. In the last part of the presentation, I want to give an overview of some questions/ideas, aiming to understand better the nature of the mechanisms giving rise to collective cell dynamics in 3D.