Tunable glassy dynamics in models of dense cellular tissue

Observations of glassy dynamics in dense cellular tissues have inspired a wealth of research modeling their collective behavior. Initial studies of the physical properties of several geometric cell models have highlighted anomalous sub-Arrhenius, or "ultrastrong," scaling of the dynamics with temperature. Here we show that the dynamics in this sub-Arrhenius regime deviate even further from the standard glassforming paradigm, displaying unusual scaling of the viscosity with temperature, a lack of breakdown of the Stokes-Einstein-Sutherland relation, and strongly suppressed dynamical heterogeneities. The dynamics in this regime, despite not possessing these hallmarks of glassy behavior, are also distinct from those of simple liquids at low temperatures. These unusual dynamical behaviors can be tuned by controlling the characteristic cell shape index of the model: decreasing this parameter tunes the model between an anomalous and a standard set of glassforming dynamics. Our results add to the growing evidence that these geometric cell models display universal features distinct from those observed in standard glassformers.