Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Post-Newtonian parameter $\gamma$ and the deflection of light in
  ghost-free massive bimetric gravity   We consider the parametrized post-Newtonian (PPN) limit of ghost-free massive
bimetric gravity with two mutually non-interacting matter sectors coupled to
the two metrics. Making use of a gauge-invariant differential decomposition of
the metric perturbations, we solve the field equations up to the linear PPN
order for a static, point-like mass source. From the result we derive the PPN
parameter $\gamma$ for spherically symmetric systems, which describes the
gravitational deflection of light by visible matter. By a comparison to its
value measured in the solar system we obtain bounds on the parameters of the
theory. We further discuss the deflection of light by dark matter and find an
agreement with the observed light deflection by galaxies. We finally speculate
about a possible explanation for the observed distribution of dark matter in
galactic mergers such as Abell 520 and Abell 3827.

21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg