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Magnetic Correlation Length and Universal Amplitude of the Lattice E_8 Ising Model

M. T. Batchelor·K. A. Seaton
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Abstract

The perturbation approach is used to derive the exact correlation length $ξ$ of the dilute A_L lattice models in regimes 1 and 2 for L odd. In regime 2 the A_3 model is the E_8 lattice realisation of the two-dimensional Ising model in a magnetic field h at T=T_c. When combined with the singular part f_s of the free energy the result for the A_3 model gives the universal amplitude $f_s ξ^2 = 0.061~728...$ as $h\to 0$ in precise agreement with the result obtained by Delfino and Mussardo via the form-factor bootstrap approach.

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M. T. Batchelor, K. A. Seaton. 1997-06-06. Magnetic Correlation Length and Universal Amplitude of the Lattice E_8 Ising Model. https://doi.org/10.1088/0305-4470%2F30%2F15%2F001

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