Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Essential finite-size effect in the 2D XY model   The thermodynamics of the 2D XY model is formulated by a transfer matrix
method and analyzed by a density matrix renormalization group. The finite-size
scaling and the beta function of the model are studied by the Roomany-Wyld
renormalization group theory. It is found that the 2D XY model has an essential
finite-size effect and the Berezinskii-Kosterlitz-Thouless transition with the
critical temperature TBKT = 0.892 appears in a finite system of 2000 - 3000
spins as a massless to massive transition with the effective critical
temperature Tc = 1.07 " 0.01.

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The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph