Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Post-Newtonian celestial mechanics in scalar-tensor cosmology   Applying the recently developed dynamical perturbation formalism on
cosmological background to scalar-tensor theory, we provide a solid theoretical
basis and a rigorous justification for phenomenological models of orbital
dynamics that are currently used to interpret experimental measurements of the
time-dependent gravitational constant. We derive the field equations for the
scalar-tensor perturbations and study their gauge freedom associated with the
cosmological expansion. We find a new gauge eliminating a prohibitive number of
gauge modes in the field equations and significantly simplifying post-Newtonian
equations of motion for localized astronomical systems in the universe with
time-dependent gravitational constant. We identify several new post-Newtonian
terms and calculate their effect on secular cosmological evolution of the
osculating orbital elements.

20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con