Comment on “Emergence and Evolution of the $k$ Gap in Spectra of Liquid and Supercritical States”

Figure 1

Dependence of the $T$ gap on density for supercritical Ar at 280 K via Eqs. (2) and (3). The Maxwell time was calculated with NIST data [5] for shear viscosity. Red symbols with error bars correspond to MD results. The inset shows the dispersion of $T$ excitations with the gap $\sim 0.27{\AA }^{-1}$, calculated from peaks of a $T$ current spectral function ${\tilde{C}}^T(k,\omega )$.