Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Correlation effects on the doped triangular lattice in view of the
  physics of sodium-rich Na$_x$CoO$_2$
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom