title: Linear response theory for hard and soft glassy materials.
abstract: Despite qualitative differences in their underlying physics, both hard and soft glassy materials exhibit almost identical linear rheological behaviors. We show that these nearly universal properties emerge naturally in a shear-transformation-zone theory of amorphous plasticity, extended to include a broad distribution of internal thermal-activation barriers. The principal features of this barrier-height distribution are predicted by nonequilibrium, effective-temperature thermodynamics. Our theoretical loss modulus G''(ω) has a peak at the α relaxation rate, and a power law decay of the form ω(-ζ) for higher frequencies, in quantitative agreement with experimental data.
authors.affiliation: Chemical Physics Department, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Bouchbinder
authors.forename: J S
authors.initials: JS
authors.lastname: Langer