Experimental study of work exchange with a granular gas: The viewpoint of the Fluctuation Theorem

Abstract

This article reports on an experimental study of the fluctuations of energy flux between a granular gas and a small driven harmonic oscillator. The DC-motor driving this system is used simultaneously as actuator and probe. The statistics of work fluctuations at controlled forcing, between the motor and the gas are examined from the viewpoint of the Fluctuation Theorem. A characteristic energy Ec of the granular gas, is obtained from this relation between the probabilities of an event and its reversal.

Nonequilibrium identities and response theory for dissipative particles

“…This result supports the validity of IFT (15) as well as its time differentiation Eq. (19). The results presented in Figs.…”

“…(19) keeps to be zero within the numerical accuracy regardless of the choice of an initial condition, where Fig. 3 begins with an equilibrium condition (t 0 = 0), and Fig.…”

“…In this subsection, we verify the validity of IFT (15) or (19) through the three-dimensional discrete element method (DEM). As stated in the text, shear is applied to x direction, and thus, y−dependence of the x component of the velocity field is affected by the presence of shear.…”

“…Therefore, the numerical verification of Eq. (19) which is the result of the correlation effects is important for Ω(Γ(t)) = 0.…”

“…Although it has been believed that these identities such as the fluctuation theorem are supported by the local time-reversal symmetry or the detailed balance condition, some experiments suggest the existence of the fluctuation theorem or related identities even in granular systems which do not have neither any time reversal symmetry nor detailed balance [16][17][18][19][20], though there exists a counter argument [21]. It is remarkable that series of papers by Puglisi and his coworkers [22][23][24][25] clarified that granular fluids do not hold the conventional fluctuation theorem but have only the second type fluctuation theorem by Evans and Searles [26].…”