Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effective interactions and superconductivity in the t-J model in the
  large-N limit   The feasibility of a perturbation expansion for Green's functions of the t-J
model directly in terms of X-operators is demonstrated using the Baym- Kadanoff
functional method. As an application we derive explicit expressions for the
kernel of the linearized equation for the superconducting order parameter in
leading order of a 1/N expansion. The linearized equation is solved numerically
on a square lattice. We find that a reasonably strong instability occurs only
for even frequency pairing with d-wavelike symmetry. Results for the transition
temperature and the effective interaction are given as a function of doping.

22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
2
The categories of this paper are: math