Sergio Ciliberto: Measuring nonequilibrium fluctuations
The lectures will be divided in two parts, one which concerns the
Fluctuation Theorem and the other the Fluctuation Dissipation theorem
when the systems is out of equilibrium.
In the first part: We study experimentally de work fluctuations
done by an external force on an harmonic oscillator in contact with an
heat bath and on a Brownian particle confined in a very nonlinear
potential. A detailed description of the experimental set-up will be
given. We also measure the fluctuations of the heat dissipated towards
the heat bath. The experimental analysis in the context of Fluctuation
Theorem (FT) allows us to discuss the importance of this theorem for
experimental systems. We discuss the finite time corrections that
depend on the observable. We also show that for the total entropy
production rate the FT is verified
for all times. We will discuss also the application of Jarzinsky Equality to experiments.
In the second part we will focus on the Fluctuations Dissipatio
theorem. Two cases will be discussed the first concerns a Brownian
particle which is driven in and out of equilibrium steady state the
other when the particle is inside an out of equilibrium bath.