Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Calculation of apsidal precession via perturbation theory   The calculus of apsidal precession frequencies of the planets is developed by
means of a perturbation thecnique. A model of concentric rings (ring model),
suitable for improving calculations, is introduced. Conclusive remarks
concerning a comparison between the theoretical, the calculated and the
observed data of the precession frequencies are performed.

9
The categories of this paper are: nlin
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an