2003/12/31 by Giovanni Gallavotti · 1 citation
Physics and Astronomy · #cond-mat.stat-mech
paper · pdf · doi:10.1063/1.1781911
published as Chaos, 14, 680--690, 2004, · This replacement (april 2004) strictly contains the first version and substantially extends it. Title change: creation -> production
arxiv created 2004/04/29 · arxiv updated 2009/12/01
Entropy might be a not well defined concept if the system can undergo transformations involving stationary nonequilibria. It might be analogous to the heat content (once called ``caloric'') in transformations that are not isochoric (i.e. which involve mechanical work): it could be just a quantity that can be transferred or created, like heat in equilibrium. The text first reviews the philosophy behind a recently proposed definition of entropy production in nonequilibrium stationary systems. A detailed technical attempt at defining the entropy of a stationary states via their variational properties follows: the unsatisfactory aspects of the results add arguments in favor of the nonexistence of a function of state to be identified with entropy; at the same time new aspects and properties of the phase space contraction emerge.