Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A rigorous treatment of the perturbation theory for many-electron
  systems   Four point correlation functions for many electrons at finite temperature in
periodic lattice are analyzed by the perturbation theory with respect to the
coupling constant. The correlation functions are characterized as a limit of
finite dimensional Grassmann integrals. A lower bound on the radius of
convergence and an upper bound on the perturbation series are obtained. The
perturbation series up to second order is numerically implemented along with
the volume-independent upper bounds on the sum of the higher order terms in 2
dimensional case.

16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org