title: Ultrametricity in the Edwards-Anderson model.
abstract: We test the property of ultrametricity for the spin-glass three-dimensional Edwards-Anderson model in zero magnetic field with numerical simulations up to 20(3) spins. We find an excellent agreement with the prediction of the mean field theory. Since ultrametricity is not compatible with a trivial structure of the overlap distribution, our result contradicts the droplet theory.
authors.affiliation: Università di Bologna, Piazza di Porta S. Donato 5, 40127 Bologna, Italy.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Contucci
authors.forename: Cristian
authors.initials: C
authors.lastname: Giardinà
authors.forename: Claudio
authors.initials: C
authors.lastname: Giberti
authors.forename: Giorgio
authors.initials: G
authors.lastname: Parisi
authors.forename: Cecilia
authors.initials: C
authors.lastname: Vernia