Universal and nonuniversal features of glassy relaxation in propylene carbonate

It is demonstrated that the susceptibility spectra of supercooled propylene carbonate as measured by depolarized-light scattering, dielectric-loss, an d incoherent quasielastic neutron-scattering spectroscopy within the GHz wi ndow are simultaneously described by the solutions of a two-component schem atic model of the mode-coupling theory (MCT) for the evolution of glassy dy namics. It is shown that the universal beta-relaxation-scaling laws, dealin g with the asymptotic behavior of the MCT solutions, describe the qualitati ve features of the calculated spectra. But the nonuniversal corrections to the scaling laws render it impossible to achieve a complete quantitative de scription using only the leading-order-asymptotic results.