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Nonconcave entropies from generalized canonical ensembles

Marius Costeniuc·Richard S. Ellis·Hugo Touchette
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Abstract

It is well-known that the entropy of the microcanonical ensemble cannot be calculated as the Legendre transform of the canonical free energy when the entropy is nonconcave. To circumvent this problem, a generalization of the canonical ensemble which allows for the calculation of nonconcave entropies was recently proposed. Here, we study the mean-field Curie-Weiss-Potts spin model and show, by direct calculations, that the nonconcave entropy of this model can be obtained by using a specific instance of the generalized canonical ensemble known as the Gaussian ensemble.

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BibTeXRIS

Marius Costeniuc, Richard S. Ellis, Hugo Touchette. 2006-05-09. Nonconcave entropies from generalized canonical ensembles. https://doi.org/10.1103/physreve.74.010105

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