Simple liquids' quasiuniversality and the hard-sphere paradigm

This presentation reflects on the well-known quasiuniversality of simple liquids’ structure and dynamics [1, 2, 3, 4, 5]. We discuss two possible justifications of it [6, 7]. The traditional one is based on the van der Waals picture of liquids in which the hard-sphere system reflects the basic physics. This paper presents an alternative explanation, which argues that all quasiuniversal liquids to a good approximation conform to the same equation of motion. This explanation uses the exponentially repulsive pair-potential system as the fundamental reference system, which in contrast to the hard-sphere system is analytical.