Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Renormalized perturbation theory for Fermi systems: Fermi surface
  deformation and superconductivity in the two-dimensional Hubbard model
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn