The second law of thermodynamics states the increase of entropy, ∆S > 0, for real processes from state A to state B at constant energy from chemistry over biological life and engines to cosmic events. The connection of entropy to information, phase-space, and heat is helpful but does not immediately convince observers of the validity and basis of the second law. This gave grounds for finding a ...

The second law of thermodynamics places constraints on state transformations. It applies to systems composed of many particles, however, we are seeing that one can formulate laws of thermodynamics when only a small number of particles are interacting with a heat bath. Is there a second law of thermodynamics in this regime? Here, we find that for processes which are approximately cyclic, the sec...

we investigate the growth of matter density perturbations as well as the generalized second law (gsl) of thermodynamics in the framework of f(r)-gravity. we consider a spatially flat frw universe filled with the pressureless matter and radiation which is enclosed by the dynamical apparent horizon with the hawking temperature. for some viable f(r) models containing the starobinsky, hu-sawicki, exp...