Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-Temperature Expansion of the Free Energy in the Two-Dimensional XY
  Model   We extend the high-temperature series of the free energy for the XY model in
two dimensions to order $\beta^{48}$ from the previous order of $\beta^{22}$ by
applying the improved algorithm of the finite lattice method. The long series
obtained enables us to conclude that the behavior of the free energy is
consistent in high accuracy with what is expected when the phase transition of
the model is of the Kosterlitz-Thouless type .

16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics