Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Asymptotically flat gravitating spinor field solutions. Step 1 - the
  statement of the problem and the comparison with confinement problem in QCD   The situation with asymptotically flat gravitating spinor field solutions is
considered. It is supposed that the problem of constructing these solutions is
connected with confinement problem in quantum chromodynamics. It is argued that
in both cases we must use a nonperturbative quantum technique.

9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
2
The categories of this paper are: math
37
The categories of this paper are: supr-con