Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase Transitions in Granular Packings   We describe the contact network of granular packings by a frustrated lattice
gas that contains steric frustration as essential ingredient. Two transitions
are identified, a spin glass transition at the onset of Reynolds dilatancy and
at lower densities a percolation transition. We describe the correlation
functions that give rise to the singularities and propose some dynamical
experiments.

37
The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
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The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: adap-org
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The categories of this paper are: econ
10
The categories of this paper are: q-bio