Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Worldine deviations and epicycles   In general relativity, only relative acceleration has an observer-independend
meaning: curvature and non-gravitational forces determine the rate at which
world lines of test bodies diverge or converge. We derive the equations
governing both in the conventional geometric formalism as well as using the
background field method. This allows us to generalize the results to test
bodies with charge and/or spin. The application of the equations to the motion
of particles in a central field results in an elegant, fully relativistic
version of the Ptolemaean epicycle scheme.

35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con