title: Fluctuation theorems for an asymmetric rotor in a granular gas.
abstract: We investigate the validity of fluctuation theorems for an asymmetric rotor experiment in a granular gas. A first state, with a Gaussian distribution of the angular velocity, is found to be well described by a first order Langevin equation. We show that fluctuation theorems are valid for the injected work and for the total entropy production. In a second state, the angular velocity distribution is double peaked due to a spontaneous symmetry breaking: A convection roll develops in the granular gas, which strongly couples to the rotor. Surprisingly, in this case, similar symmetry relations hold, which lead to a good prediction for the height ratio of the two peaks.
authors.affiliation: Physics of Fluids, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Joubaud
authors.forename: Detlef
authors.initials: D
authors.lastname: Lohse
authors.forename: Devaraj
authors.initials: D
authors.lastname: van der Meer