Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spherically Symmetric Approximation (and beyond) in Relativistic
  Schroedinger Theory   The energy eigenvalue problem of non-relativistic positronium is considered
within the framework of Relativistic Schroedinger Theory (RST), and the results
are compared to those of the conventional quantum theory. For the range of
princi- pal quantum numbers n = 2;3;::: ;30, the RST predictions for the
non-relativistic positronium energies deviate now from the corresponding
predictions of the conven- tional quantum theory at an average of (roughly) 3%.
These results suggest that the deviations will be further diminished in the
higher orders of approximation.

3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg