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Equilibrium states and their entropy densities in gauge-invariant C*-systems

N. Akiho·F. Hiai·D. Petz
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Abstract

A gauge-invariant C*-system is obtained as the fixed point subalgebra of the infinite tensor product of full matrix algebras under the tensor product unitary action of a compact group. In the paper, thermodynamics is studied on such systems and the chemical potential theory developed by Araki, Haag, Kastler and Takesaki is used. As a generalization of quantum spin system, the equivalence of the KMS condition, the Gibbs condition and the variational principle is shown for translation-invariant states. The entropy density of extremal equilibrium states is also investigated in relation to macroscopic uniformity.

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N. Akiho, F. Hiai, D. Petz. 2005-03-16. Equilibrium states and their entropy densities in gauge-invariant C*-systems. https://doi.org/10.1142/s0129055x05002352

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