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TEST OF THE GALLAVOTTI-COHEN SYMMETRY IN A STOCHASTIC MODEL WITH NON EQUILIBRIUM STATIONARY STATES. Giuseppe Gonnella Antonio Lamura Antonio Piscitelli. Equilibrium stationary states. Gibbs-Boltzmann distribution. Non equilibrium stationary states (N.E.S.S.). -Thermal gradient
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TEST OF THE GALLAVOTTI-COHEN SYMMETRY IN A STOCHASTIC MODEL WITH NON EQUILIBRIUM STATIONARY STATES Giuseppe Gonnella Antonio Lamura Antonio Piscitelli
Equilibrium stationary states Gibbs-Boltzmann distribution Non equilibrium stationary states (N.E.S.S.) -Thermal gradient -Energy flow imposed by the extern Single brownian particle dragged through water by a laser induced moving potential Force exerted on the particle Work done on the system over a time interval from to E.G.D.Cohen, R.van Zon PHYS.REV.E 69,056121
GALLAVOTTI-COHEN SYMMETRY FOR N.E.S.S. Ergodic non equilibrium stationary states: Trajectory in phase space Total energy injected into the system, work done by the extern, over a time interval Average of the average values of over the subsequent intervals of time along the history e Poniamo
Probability distribution function that the ratio assumes the value in the time interval The theorem suggests that: in a non equilibrium stationary state the probability distribution function satisfies that where is called Symmetry Function
TEST OF GALLAVOTTI-COHEN SYMMETRY IN STOCHASTIC LANGEVIN SYSTEM FOR BINARY MIXTURES The model: = order parameter Evolution equation: with: (Noise verifies the fluctuation-dissipation relation) and NOTE: This model is used in practise in the quite general framework of the study of phase separation (with r<0) and of mixtures dynamics with a convective term, when the fluctuations of the velocity field are negligible.
POWER DEFINITION IN SYSTEMS WITH SHEAR = Pressure tensor Power density= (De Groot-Mazur) Non diagonal part of pressure tensor = (A.J.M.Yang, P.D.Fleming, J.H.Gibbs, Journal of Chemical Physics, vol.64, No.9)
Probability distribution function for shear direction direction opposite to that of the shear y y x x
We work above the critical temperature Remember that is an increasing function of . Can be found more on this topic on F.Corberi,G.Gonnella,E.Lippiello,M.Zannetti, J.Phys.A:Math.Gen. 36 No 17 4729-4755
GENERAL BEHAVIOUR OF THE SYSTEM Temporal correlation of Correlation of stress time spent by C(X) for reaching at 95% its stationary value. Configuration at a stationary time
SOME RESULTS
CONCLUSIONS It has been measured the correlation time (of and ) and it has been verified that the characteristics and the behaviour of the system are typical of a stationary state above the critical temperature. From the simulations performed until now the limit slope (1 for GC symmetry) seems to vary with and in particular seems to increase with NEXT STEPS To state with more precision the above result for understanding better the trend of the limit slope with To approach the problem analytically