 
Summary: Journal of Chemical Physics 128 (2008) 154506 (7 pages)
Fluctuation theorem and mesoscopic chemical clocks
David Andrieux and Pierre Gaspard
Center for Nonlinear Phenomena and Complex Systems,
Universit´e Libre de Bruxelles, Code Postal 231, Campus Plaine, B1050 Brussels, Belgium
The fluctuation theorems for dissipation and the currents are applied to the stochastic version
of the reversible Brusselator model of nonequilibrium oscillating reactions. It is verified that the
symmetry of these theorems holds far from equilibrium in the regimes of noisy oscillations. Moreover,
the fluctuation theorem for the currents is also verified for a truncated Brusselator model.
PACS numbers: 82.20.Uv; 05.70.Ln; 02.50.Ey
I. INTRODUCTION
The socalled fluctuation theorems suggest that general relationships might hold for fluctuations in nonequilib
rium systems [116]. In such systems, these relationships establish a symmetry between the forward and reversed
fluctuations of dissipation or currents, showing that the ratio of their probability distributions is related to the De
Donder affinities, i.e., the thermodynamic forces driving the system out of equilibrium [17]. The fluctuation theorems
appear to play an important role in nonequilibrium statistical thermodynamics because they allow us to obtain re
sults generalizing Onsager's reciprocity relations to the nonlinear response coefficients [13, 16]. Albeit early work has
envisaged such relationships in mechanical systems, they have recently been extended to reacting systems described
by stochastic processes [9, 1214]. In this context, we may wonder how far from equilibrium the fluctuation theorems
might hold. Such a theorem has already been shown to hold in bistable nonequilibrium reactions as in the Schl¨ogl
