title: Directed and undirected multiurn models in a one-dimensional ring.
abstract: The flea model by Ehrenfest describes the jumps of a fixed number of fleas between two dogs. In each time step a randomly selected flea jumps on the other dog. We study directed and undirected multiurn models in a one-dimensional ring. The introduced models represent generalizations of three recently proposed multiurn models which themselves are generalizations of Ehrenfest's model. The models are solved analytically. For the directed case we find oscillations of the average number of balls or fleas in a certain urn before the system reaches its equilibrium state. The discussed models may serve as basic models of dynamics of granular media in connected periodic compartment systems.
authors.affiliation: Institut für Theoretische Physik, Fachbereich 1, Universität Bremen, Otto-Hahn-Allee, D-28334 Bremen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Nagler