Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Response to a twist on systems with Zp symmetry   We study response to a twist in the two-dimensional p-state clock model,
which has the discrete Zp symmetry. The response is measured in terms of
helicity modulus, which is usually defined with respect to an infinitesimal
twist. However, we demonstrate that such a definition is inappropriate for the
clock model. The helicity modulus must be defined with respect to a finite,
quantized twist which matches the discrete Zp symmetry of the model. Recent
numerical results, which casted doubt on the standard picture that two
Berezinskii-Kosterlitz-Thouless transitions occur for p > 4, are rather a
consequence of use of the inappropriate quantity. Numerical calculation of the
appropriately defined helicity modulus indeed supports the standard picture.

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The categories of this paper are: quant-ph
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
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The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin