Scaling of fluctuations in a colloidal glass

We report experimental measurements of particle dynamics in a colloidal glass in order to understand the dynamical heterogeneities associated with the cooperative motion of the particles in the glassy regime. We study the local and global fluctuation of correlation and response functions in an aging colloidal glass. The observables display universal scaling behavior following a modified power-law, with a plateau dominating the less heterogeneous short-time regime and a power-law tail dominating the highly heterogeneous long-time regime.