Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Equatorial symmetry/antisymmetry of stationary axisymmetric electrovac
  spacetimes   Two theorems are proved concerning how stationary axisymmetric electrovac
spacetimes that are equatorially symmetric or equatorially antisymmetric can be
characterized correctly in terms of the Ernst potentials $\E$ and $\Phi$ or in
terms of axis-data.

11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph