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Variational method and duality in the 2D square Potts model

L. Angelini·M. Pellicoro·I. Sardella·M. Villani
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Abstract

The ferromagnetic q-state Potts model on a square lattice is analyzed, for q>4, through an elaborate version of the operatorial variational method. In the variational approach proposed in the paper, the duality relations are exactly satisfied, involving at a more fundamental level, a duality relationship between variational parameters. Besides some exact predictions, the approach is very effective in the numerical estimates over the whole range of temperature and can be systematically improved.

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L. Angelini, M. Pellicoro, I. Sardella, M. Villani. 1997-05-07. Variational method and duality in the 2D square Potts model. https://doi.org/10.1088/0305-4470%2F30%2F22%2F008

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