Figure 2. Pressure dependence of the normalized ω_b(P )/ω_b(0) BP frequency and the normalized sound velocity V_s(P )/V_s(0) for the Kel F-800 polymer glass.

The fitting procedures applied for the determination of peak frequency of the asymmetric Boson band can be found elsewhere²⁰,³⁴. The inset shows fitting attempts of ω_b, using equation (1), for three different values of the parameter P₀.