title: Contact network topology in tapped granular media.
abstract: We analyze the contact network of simulated two-dimensional granular packings in different states of mechanical equilibrium obtained by tapping. We show that topological descriptors of the contact network allow one to distinguish steady states of the same mean density obtained with different tap intensities. These equal-density states were recently proven to be distinguishable through the mean force moment tensor. In contrast, geometrical descriptors, such as radial distribution functions, bond order parameters, and Voronoi cell distributions, can hardly discriminate among these states. We find that small-order loops of contacts-the polygons of the network-are especially sensitive probes for the contact structure.
authors.affiliation: CNR-SPIN, Dipartimento di Scienze Fisiche, Universitá di Napoli Federico II, Naples, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Arévalo
authors.forename: Luis A
authors.initials: LA
authors.lastname: Pugnaloni
authors.forename: Iker
authors.initials: I
authors.lastname: Zuriguel
authors.forename: Diego
authors.initials: D
authors.lastname: Maza
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D008958:Models, Molecular; D013499:Surface Properties
chemical_list: D003102:Colloids