On the thermodynamical equivalence of physical systems

Salvino Ciccariello

Published 2014-12-29Version 1

Two different physical systems are said to be thermodynamically equivalent if one of the thermodynamical potentials of the first system is proportional to the corresponding potential of the second system after expressing the state variables of the first system in terms of those of the second by a reversible transformation. One reports three pairs of physical systems that are thermodynamically equivalent. They are: the one dimensional ideal gas and the one dimensional hard rod fluid, any pair of fluids characterized by interactions that coincide by a scaling of the distance and the coupling constant, and the ideal Fermi and classical gases.