Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evolution of gravitational orbits in the expanding universe   The gravitational action of the smooth energy-matter components filling in
the universe can affect the orbit of a planetary system. Changes are related to
the acceleration of the cosmological scale size R. In a universe with
significant dark matter, a gravitational system expands or contracts according
to the amount and equation of state of the dark energy. At present time, the
Solar system, according to the LambdaCDM scenario emerging from observational
cosmology, should be expanding if we consider only the effect of the
cosmological background. Its fate is determined by the equation of state of the
dark energy alone. The mean motion and periastron precession of a planet are
directly sensitive to (d^2 R/d t^2)/R, whereas variations with time in the
semi-major axis and eccentricity are related to its time variation. Actual
bounds on the cosmological deceleration parameters q_0 from accurate
astrometric data of perihelion precession and changes in the third Kepler's law
in the Solar system fall short of ten orders of magnitude with respect to
estimates from observational cosmology. Future radio-ranging measurements of
outer planets could improve actual bounds by five orders of magnitude.

17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th