Abstract
In a recent Letter, Wang and Brady (WB) [1] analyse the rheology of Brownian hard spheres using constant stress and pressure Brownian dynamics simulations. The main observable is the shear viscosity, η( ̇γ,Π), expressed as a function of the shear rate ̇γ and adimensional pressure ̄Π = Πa3/(kBT), where Π is the pressure, kBT the thermal energy, and a the average particle diameter. The central conclusion is the discovery of a “universal viscosity divergence”