title: Single flow snapshot reveals the future and the past of pairs of particles in turbulence.
abstract: We develop an analytic formalism and derive new exact relations that express the short-time dispersion of fluid particles via the single-time velocity correlation functions in homogeneous isotropic and incompressible turbulence. The formalism establishes a bridge between single-time Eulerian and long-time Lagrangian pictures of turbulent flows. In particular, we derive an exact formula for a short-term counterpart of the long-time Richardson law, and we identify a conservation law of turbulent dispersion which is true even in nonstationary turbulence.
authors.affiliation: Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Gregory
authors.initials: G
authors.lastname: Falkovich
authors.forename: Anna
authors.initials: A
authors.lastname: Frishman