The study of thermodynamic problems in quantum system. The role of correlations in work extraction and entropy productions. Feedback controllers in quantum heat engine and the effects on work and heat. One shot thermodynamics. The building of minimal heat engine able to extract work from quantum systems. New bounds on entropy variations in presence of Maxwell's Demon. The application of modified theory of gravitation to the early phase of the universe and to the actual expansion as explanation of dark energy. Predictions about the mass of massive neutrinos (Seesaw mechanism) from leptogenesis and the potential of chamaleon field in the Universe.