Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological boundary modes in jammed matter   Granular matter at the jamming transition is poised on the brink of
mechanical stability, and hence it is possible that these random systems have
topologically protected surface phonons. Studying two model systems for jammed
matter, we find states that exhibit distinct mechanical topological classes,
protected surface modes, and ubiquitous Weyl points. The detailed statistics of
the boundary modes enable tests of a standard understanding of the detailed
features of the jamming transition, and show that parts of this argument are
invalid.

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The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
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The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
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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: nlin
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The categories of this paper are: econ
2
The categories of this paper are: math