title: Protocol-independent granular temperature supported by numerical simulations.
abstract: A possible approach to the statistical description of granular assemblies starts from Edwards's assumption that all blocked states occupying the same volume are equally probable [Edwards and Oakeshott, Physica A 157, 1080 (1989)]. We performed computer simulations using two-dimensional polygonal particles excited periodically according to two different protocols: excitation by pulses of "negative gravity" and excitation by "rotating gravity." The first protocol exhibits a nonmonotonous dependency of the mean volume fraction on the pulse strength. The overlapping histogram method is used in order to test whether the volume distribution is described by a Boltzmann-like distribution and to calculate the inverse compactivity as well as the logarithm of the partition sum. We find that the mean volume is a unique function of the measured granular temperature, independently of the protocol and of the branch in ϕ(g), and that all determined quantities are in agreement with Edwards's theory.
authors.affiliation: Institute for Theoretical Physics, Otto von Guericke University Magdeburg, Postfach 4120, D-39106 Magdeburg, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Becker
authors.affiliation: Institute for Theoretical Physics, Otto von Guericke University Magdeburg, Postfach 4120, D-39106 Magdeburg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Kassner