@article{b0dd8bc0d07211db9c7c000ea68e967b,
title = "Single-order-parameter description of glass-forming liquids: A one-frequency test",
abstract = "Thermoviscoelastic linear-response functions are calculated from the master equation describing viscous liquid inherent dynamics. From the imaginary parts of the frequency-dependent isobaric specific heat, isothermal compressibility, and isobaric thermal expansion coefficient, we define a {"}linear dynamic Prigogine-Defay ratio{"} with the property that if this ratio is unity at one frequency, then it is unity at all frequencies. This happens if and only if there is a single-order-parameter description of the thermoviscoelastic linear responses via an order parameter which may be nonexponential in time. Generalizations to other cases of thermodynamic control parameters than temperature and pressure are also presented.",
author = "Ellegaard, \{Niels Langager\} and Christensen, \{Tage Emil\} and Christiansen, \{Peder Voetmann\} and Olsen, \{Niels Boye\} and Pedersen, \{Ulf R{\o}rb{\ae}k\} and Thomas Schr{\o}der and Jeppe Dyre",
year = "2007",
doi = "10.1063/1.2434963",
language = "English",
volume = "126",
pages = "074502--1 -- 074502--8",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics",
number = "7",
}