Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ensemble inequivalence : Landau theory and the ABC model   It is well known that systems with long-range interactions may exhibit
different phase diagrams when studied within two different ensembles. In many
of the previously studied examples of ensemble inequivalence, the phase
diagrams differ only when the transition in one of the ensembles is first
order. By contrast, in a recent study of a generalized ABC model, the canonical
and grand-canonical ensembles of the model were shown to differ even when they
both exhibit a continuous transition. Here we show that the order of the
transition where ensemble inequivalence may occur is related to the symmetry
properties of the order parameter associated with the transition. This is done
by analyzing the Landau expansion of a generic model with long-range
interactions. The conclusions drawn from the generic analysis are demonstrated
for the ABC model by explicit calculation of its Landau expansion.

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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
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The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: econ
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The categories of this paper are: math