Résumé:

We investigate by rheology and light scattering the influence of the elastic modulus, G(0), on the slow dynamics and the aging of a soft glass. We show that the slow dynamics and the aging can be entirely described by the evolution of an effective viscosity, eta(eff), defined as the characteristic time measured in a stress relaxation experiment times G(0). At all times, eta(eff) is found to be independent of G(0), of elastic perturbations, and of the rate at which the sample is quenched in the glassy phase. We propose a simple model that links eta(eff) to the internal stress built up at the fluid-to-solid transition.