We prove a transient fluctuation theorem for the currents for continuous-time
Markov jump processes with stationary rates, generalizing an asymptotic result
by Andrieux and Gaspard [J. Stat. Phys. 127, 107 (2007)] to finite times. The
result is based on a graph theoretical decomposition in cycle currents and an
additional set of tidal currents that characterize the transient relaxation
regime. The tidal term can then be removed by a preferred choice of a suitable
initial equilibrium ensemble, a result that provides the general theory for the
fluctuation theorem without ensemble quantities recently addressed in [Phys.
Rev. E 89, 052119 (2014)]. As an example we study the reaction network of a
simple stochastic chemical engine, and finally we digress on general properties
of fluctuation relations for more complex chemical reaction networks.Comment: 19 pages, 2 figures. Sign error corrected in Eq.(50) and followin
