Comment on "Crossover of collective modes and positive sound dispersion   in supercritical state"
  We comment on an expression for positive sound dispersion (PSD) in fluids and analysis of PSD from molecular dynamics simulations reported in the Letter by Fomin et al (J.Phys.:Condens.Matt. v.28, 43LT01, 2016) 
T. Bryk, I. Mryglod
cond-mat.soft cond-mat.dis-nn