Generic Primary Mechanical Response of Viscous Liquids

Four decades ago a seminal review by Jonscher [Nature (London) 267, 673 (1977)] revealed that the dielectric response of conducting materials is characterized by a remarkable universality. Demonstrating that the same response pattern is exhibited also by shear rheological spectra of nonpolymeric viscous liquids, the present contribution connects two branches of condensed matter physics: Concepts developed for charge transport can be employed for the description of mass flowand vice versa. Based on the virtual equivalence of the two dynamics a connection is established between microscopic and macroscopic viscoelastic characteristics of liquids, resembling the Barton-Nakajima-Namikawa relation for conductivity.