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Thermodynamics of the two--dimensional O(3) non linear sigma model with Fixed-Point lattice action

S. P. Spiegel
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Abstract

We calculate the free energy density of the two dimensional O(3) non linear sigma model over a large temperature region. At high temperatures the calculations could be done by perturbation theory whereas in the low temperature regime we used Monte-Carlo simulations. Using the Fixed--Point action the results do not show any remarkable cut-off effects and furthermore the behaviour of these effects is nearly the same over the whole temperature region. The results of the Fixed-Point action are then compared to those of the standard Wilson action.

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S. P. Spiegel. 1996-11-26. Thermodynamics of the two--dimensional O(3) non linear sigma model with Fixed-Point lattice action. https://doi.org/10.1016/s0370-2693(97)00346-8

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