content_image/343270.jpg
<img src='content_image/343270.jpg'>

and the phases collapse fairly well on a single master curve, as predicted by Eq. (1). A weak departure from scaling occurs at low ω for the highest T . This is not surprising: scaling should not hold far above T$_{g}$ , where the dynamical correlations become short-ranged [12, 13]. Furthermore, the nonlinear response results both from trivial dielectric saturation effects [15, 21, 22] (always present for ωτ < 1), and from the non trivial dynamical correlations contribution. As the latter vanishes when ω → 0 ([12, 13]), the contribution of the trivial saturation effect should dominate at high T and low ω . The observed departure from scaling can thus be explained by the different T and ω dependencies of the two contributions. 

Figure 3 gives the T dependence of the maximum value of X ( ω, T ), reached for ω = ω ∗ = 2 πf ∗ . Since scaling is well obeyed, Eq. (1) tells us that this maximum value is proportional to N$_{corr}$ ( T ). A clear increase of this quantity as T decreases toward T$_{g}$ is visible in Fig. 

