1/f noise and dynamical heterogeneity in glasses.

We investigate the relationship between two experimental sets of data related to dynamical heterogeneity, the coefficient alpha of 1/f(alpha) dipolar noise derived from the nonexponentiality of the dielectric or magnetic response near and above the mean relaxation time, and the range Delta(z) of the relaxation times. We find that in different classes of glasses, including spin and proton glasses, relaxor materials, and glass-forming liquids, this relationship exhibits the same trend.