Study of the Rytov dip for liquid o-terphenyl

Light scattering spectra in the depolarized configuration are presented for the fragile glass former o-terphenyl in the temperature range between 350 and 421 K. These spectra are characterized by the presence of the Rytov dip and have been analysed in terms of the two-variable model of Andersen and Pecora. This model works well in the whole temperature range explored, that is over a range where the shear viscosity varies by almost one decade. The coupling parameter R is extracted and turns out to be almost temperature independent and very similar to that derived for other studied systems.