Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Particle-hole symmetry of charge excitation spectra in the paramagnetic
  phase of the Hubbard model
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat