title: Topological analysis of tapped granular media using persistent homology.
abstract: We use the first Betti number of a complex to analyze the morphological structure of granular samples in mechanical equilibrium. We investigate two-dimensional granular packings after a tapping process by means of both simulations and experiments. States with equal packing fraction obtained with different tapping intensities are distinguished after the introduction of a filtration parameter which determines the particles (nodes in the network) that are joined by an edge. This is accomplished by just using the position of the particles obtained experimentally and no other information about the possible contacts, or magnitude of forces.
authors.affiliation: Departamento de Física, Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Ardanza-Trevijano
authors.affiliation: Departamento de Física, Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona, Spain.
authors.forename: Iker
authors.initials: I
authors.lastname: Zuriguel
authors.affiliation: CNR-SPIN, Dipartimento di Scienze Fisiche, Università di Napoli Federico II, I-80126 Napoli, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Arévalo
authors.affiliation: Departamento de Física, Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Maza