Tuning the glassy dynamics in models of dense epithelial tissue

Densely packed epithelial tissues have been shown to exhibit dynamics analogous to those in glassy materials. This observation has inspired a host of research using coarse-grained geometric cell models to describe their emergent collective behavior. Initial studies of the glassy dynamics of several of these models have revealed anomalous sub-Arrhenius scaling of the relaxation dynamics in parameter regimes relevant to real cells. Here we show that in the 2d Voronoi model this “ultra-strong” behavior deviates further still from the standard glassforming paradigm, corresponding to a regime where the viscosity does not diverge and dynamical heterogeneities are highly suppressed. Varying the characteristic shape index 𝑝₀ allows the system properties to be tuned between this dynamically homogeneous regime and that of a standard glassformer. Our results further emphasize the abnormal material properties of these models and highlight a need for better understanding of their applicability to real cellular tissue.