title: Perturbation spreading in many-particle systems: a random walk approach.
abstract: The propagation of an initially localized perturbation via an interacting many-particle Hamiltonian dynamics is investigated. We argue that the propagation of the perturbation can be captured by the use of a continuous-time random walk where a single particle is traveling through an active, fluctuating medium. Employing two archetype ergodic many-particle systems, namely, (i) a hard-point gas composed of two unequal masses and (ii) a Fermi-Pasta-Ulam chain, we demonstrate that the corresponding perturbation profiles coincide with the diffusion profiles of the single-particle Lévy walk approach. The parameters of the random walk can be related through elementary algebraic expressions to the physical parameters of the corresponding test many-body systems.
authors.affiliation: School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: V
authors.initials: V
authors.lastname: Zaburdaev
authors.forename: S
authors.initials: S
authors.lastname: Denisov
authors.forename: P
authors.initials: P
authors.lastname: Hänggi