Speaker
Prof.
Andreas Engel
(University of Oldenburg)
Description
Non-equilibrium work and fluctuation theorems highlight the
large-deviation properties of thermodynamic quantities.
Accordingly the tails of the probability densities of work,
heat, or entropy are of special importance. However, by
their very definition rare realizations from these tails are
difficult to observe in experiments or simulations and the
resulting histograms are imprecise exactly in the region of
highest interest.
The situation may be improved by combining the histograms
with analytical expressions for the asymptotics of the
probability distributions. In the case of driven Langevin
systems the asymptotic behaviour of the work distribution
can be determined from a saddle-point approximation in the
functional integral describing the transformation of
probability from the trajectory to the work. The calculation
of the pre-exponential factor may improve the accuracy of
the method substantially and allows to combine histogram and
asymptotics without adjustable parameters. For the special
case of harmonic potentials with time-dependent frequency
the asympotitics of the work distribution is always exponential.
Primary author
Prof.
Andreas Engel
(University of Oldenburg)
