Thermal diffusivity of glycerol at the liquid-glass transition

After a brief review of the dynamics of viscous liquids near the liquid-glass transition, the response of glycerol to the application of a heat pulse is calculated using a generalized hydrodynamic model. Data obtained by other authors are used to set the values of the parameters involved in the model. Experiments, performed with the forced Rayleigh light scattering technique, are presented and analysed. This leads to new results concerning the dispersion of sound at low temperature and the relaxation time of the thermal diffusivity. A few spectra are presented to show that the generalized hydrodynamic model that we use is adequate to describe accurately the present experimental results.