Reply to comment on "Probing the equilibrium dynamics of colloidal hard spheres above the mode-coupling glass transition

Abstract

[1] (RWF) use mode-coupling theory (MCT) to analyze a subset of our data [2] and question our claim that dense colloidal hard spheres enter at large volume fraction ’, a dynamical regime not described by MCT. To reach this conclusion, RWF fit intermediate scattering functions (ISFs) obtained by light scattering to the outcome of MCT calculations for a monodisperse system of hard spheres. By freely adjusting the short-time diffusion coefficient Ds, and w, the parameter fixing the relative contribution of self and collective dynamics to the signal, they reproduce well the short-time decay of the data to a plateau. More crucially, to reproduce also the long-time decay, RWF need to adjust, for each experimental volume fraction ’ considered, the volume fraction ’mct of the corresponding theoretical curve. Since the shape of the ISF does not change much with ’, this analysis is nearly equivalent to adjusting the typical relaxation time ð’Þ, which we had done more simply by fitting the data to a stretched exponential form [2].