Variations on Mechanics The Koopman–von Neumann (KvN) theory is a description of classical mechanics as an operatorial theory similar to quantum mechanics, based on a Hilbert space of complex, square-integrable wavefunctions. As its name suggests, the KvN theory is related to work by Bernard Koopman and John von Neumann. https://en.wikipedia.org/wiki/Koopman–von_Neumann_classical_mechanics | Shamoon Ahmed