Fabio Marchesoni

Single molecule experiments are a valuable source of knowledge and information even from a physicist’s viewpoint. We discuss how RNA folding-unfolding experiments can greatly contribute to elucidate the role of large fluctuations in non-equilibrium statistical physics. Non-equilibrium thermodynamics of small systems describes energy exchange processes between a system and its environment in the low energy range (a few k_BT) where Brownian fluctuations are dominant. This new approach to the notion of fluctuation is aimed to identify the building blocks of a general theory describing energy fluctuations in non-equilibrium processes occurring in systems ranging from condensed matter physics to biophysics. In particular, recently formulated fluctuation theorems and path thermodynamics can be used to extract information from current single-molecule experiments.