Regensburg 2025 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 3: Active Matter I (joint session DY/BP/CPP)
DY 3.10: Talk
Monday, March 17, 2025, 12:15–12:30, H37
Active nematic turbulence with substrate friction — •Peter A. E. Hampshire1,2 and Ricard Alert1,2,3 — 1Max Planck Institute for the Physics of Complex Systems, Dresden, Germany — 2Center for Systems Biology Dresden, Dresden, Germany — 3Cluster of Excellence Physics of Life, Dresden, Germany
Active nematics with high activity exhibit turbulent-like flows, characterized by vortices, spatio-temporal chaos and power laws in the energy spectra [1-3]. Continuum models have been successfully used to predict the scaling of the energy spectra with the wavevector. Most theoretical work has focused on free-standing, active nematic films. However, in several experimental realisations, such as bacterial colonies and epithelial monolayers, the active nematic is in contact with a solid substrate. We generalised a 2D, incompressible active nematic model to include substrate friction, and studied its impact on the transition to turbulence and the energy spectra of the turbulent-like flows. We find a variety of dynamic states including flow in lanes, stable vortices and both isotropic and anisotropic turbulence. At high activity and moderate friction, we found a power-law scaling in the kinetic energy spectrum E(q) ∼ q3, where q is the wavevector, at low wavevectors. The exponent of 3 can be justified with a power-counting argument. Overall, we have developed a model for active nematic turbulence on a substrate that can be compared to biological systems. [1] L. Giomi, Phys. Rev. X 5, 031003 (2015). [2] R. Alert, J.-F. Joanny, J. Casademunt, Nat. Phys. 16, 682-688 (2020). [3] B. Martínez-Prat*, R. Alert*, et al., Phys. Rev. X 11, 031065 (2021).
Keywords: active; nematic; turbulence; friction