Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Invariant expansion for the trigonal band structure of graphene
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph