Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermodynamics of the two--dimensional O(3) non linear sigma model with
  Fixed-Point lattice action   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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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: patt-sol