A characterization of the entropy functionals for grand canonical ensembles. The discrete case

Summary ? Natural ? properties lead to a representation theorem for the entropy functional of a grand canonical ensemble. In addition to the classical Boltzmann term, the representation contains three more terms that seem to be meaningful in statistical mechanics.

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Sunto Da proprietà ? naturali ? imposte al funzionale entropia di un insieme gran canonico si deduce un teorema di rappresentazione per esso. In aggiunta al termine classico di Boltzmann, la rappresentazione mette in luce tre ulteriori termini che sembrano significativi in meccanica statistica.

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A Dario Graffi per il suo 70° compleanno

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Entrata in Redazione il 17 marzo 1976.

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While on sabbatical leave of absence from the University of Waterloo, Canada, Department of Applied Mathematics.

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Research supported in part by National Research Council of Canada, grant A-7677 and IBM-Italia.