2007/03/30 by Sylvain Joubaud, Nicolas Garnier, S. Ciliberto +1 · 1 citation
Engineering · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Quantum Electrodynamics and Casimir Effect #Thermal Radiation and Cooling Technologies #cond-mat.stat-mech
paper · pdf · doi:10.1088/1742-5468/2007/09/p09018
published as Journal of Statistical Mechanics: Theory and Experiment 09 (2007) P09018
arxiv created 2007/03/30 · openalex publication_date 2007/09/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
We study experimentally the thermal fluctuations of energy input and dissipation in a harmonic oscillator driven out of equilibrium, and search for fluctuation relations. Both the transient evolution from the equilibrium state, and non-equilibrium steady states are analyzed. Fluctuation relations are obtained experimentally for both the work and the heat, for the stationary and transient evolutions. A stationary state fluctuation theorem is verified for various time dependences of the imposed external torque. The transient fluctuation theorem is satisfied for the work given to the system but not for the heat dissipated by the system in the case of linear forcing. Experimental observations on the statistical and dynamical properties of the position fluctuations of the torsion pendulum allow us to derive analytical expressions for the probability density functions of the work and the heat. We obtain for the first time an analytic expression for the probability density function of the heat. The agreement between experiments and our predictions is excellent.