A continuous-time random-walk approach to the Cole-Davidson dielectric response of dipolar liquids

We show how the Cole-Davidson relaxation response, characteristic of alcoholic systems, can be derived within the framework of the continuous-time random walk (CTRW). Using the random-variable formalism, we indicate that the high-frequency power law of dielectric spectra is determined by the heavy-tailed distribution of quantities that provide the spatio-temporal coupling in the random-walk process. As an illustration, we present the dielectric permittivity spectra of several butanediol isomers.