A kinetic scheme that closes the BBGKY hierarchy without truncating it at the Boltzmann (lowest) level: a relaxation-time-like approximation designed to account, in principle, for the entire coupled chain of N-particle distribution equations. Worked explicitly at the second level of the hierarchy, it is used to compute the spectra of conserved-operator correlation functions in a gas of weakly confined hadrons, and shows how the higher hierarchy levels capture ultraviolet structure of the operator spectra, which is compared against results from holographic duality.
In classical kinetic theory, the BBGKY hierarchy is an infinite chain of integro-differential equations that describes the full time-reversal-invariant (Liouville) system of interacting (quasi)-parti…