title: Brownian forces in sheared granular matter.
abstract: We present results from a series of experiments on a granular medium sheared in a Couette geometry and show that their statistical properties can be computed in a quantitative way from the assumption that the resultant from the set of forces acting in the system performs a Brownian motion. The same assumption has been utilized, with success, to describe other phenomena, such as the Barkhausen effect in ferromagnets, and so the scheme suggests itself as a more general description of a wider class of driven instabilities.
authors.affiliation: Dipartimento di Fisica, Università La Sapienza, Piazzale le Aldo Moro 2, 00185 Roma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Baldassarri
authors.forename: F
authors.initials: F
authors.lastname: Dalton
authors.forename: A
authors.initials: A
authors.lastname: Petri
authors.forename: S
authors.initials: S
authors.lastname: Zapperi
authors.forename: G
authors.initials: G
authors.lastname: Pontuale
authors.forename: L
authors.initials: L
authors.lastname: Pietronero