Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Antiferromagnetism, charge density wave, and d-wave superconductivity in
  the extended $t$--$J$--$U$ model: role of intersite Coulomb interaction and a
  critical overview of renormalized mean field theory
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an