Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Green Function Theory of Strongly Correlated Electron Systems   A novel effective Hamiltonian in the subspace of singly occupied states is
obtained by applying the Gutzwiller projection approach to a generalized
Hubbard model with the interactions between two nearest- neighbor sites. This
model provides a more complete description of the physics of strongly
correlated electron systems. The system is not necessarily in a ferromagnetic
state as temperature approaches zero at any doping level. The system, however,
must be in an antiferromagnetic state at the origin of the doping-temperature
plane. Moreover, the model exhibits superconductivity in a doped region at
sufficiently low temperatures. We summarize the studies and provide a phase
diagram of the antiferromagnetism and the superconductivity of the model in the
doping-temperature plane here. Details will be presented in subsequent papers.

18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol