# Resolving the debate about proposed expressions for the classical entropy

@article{Swendsen2017ResolvingTD, title={Resolving the debate about proposed expressions for the classical entropy}, author={Robert H. Swendsen}, journal={arXiv: Statistical Mechanics}, year={2017} }

Despite well over a century of effort, the proper expression for the classical entropy in statistical mechanics remains a subject of debate. The Boltzmann entropy (calculated from a surface in phase space) has been criticized as not being an adiabatic invariant. It has been suggested that the Gibbs entropy (volume in phase space) is correct, which would forbid the concept of negative temperatures. An apparently innocuous assumption turns out to be responsible for much of the controversy, namely…

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