Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonlinear spinor field equations in gravitational theory: spherical
  symmetric soliton-like solutions   This paper deals with an extension of a previous work [Gravitation &
Cosmology, Vol. 4, 1998, pp 107--113] to exact spherical symmetric solutions to
the spinor field equations with nonlinear terms which are arbitrary functions
of $S=\bar{\psi}\psi $, taking into account their own gravitational field.
Equations with power and polynomial nonlinearities are studied in detail. It is
shown that the initial set of the Einstein and spinor field equations with a
power nonlinearity has regular solutions with spinor field localized energy and
charge densities. The total energy and charge are finite. Besides, exact
solutions, including soliton - like solutions, to the spinor field equations
are also obtained in flat space-time.

36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an