Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Testing General Relativity with Present and Future Astrophysical
  Observations   One century after its formulation, Einstein's general relativity has made
remarkable predictions and turned out to be compatible with all experimental
tests. Most of these tests probe the theory in the weak-field regime, and there
are theoretical and experimental reasons to believe that general relativity
should be modified when gravitational fields are strong and spacetime curvature
is large. The best astrophysical laboratories to probe strong-field gravity are
black holes and neutron stars, whether isolated or in binary systems. We review
the motivations to consider extensions of general relativity. We present a
(necessarily incomplete) catalog of modified theories of gravity for which
strong-field predictions have been computed and contrasted to Einstein's
theory, and we summarize our current understanding of the structure and
dynamics of compact objects in these theories. We discuss current bounds on
modified gravity from binary pulsar and cosmological observations, and we
highlight the potential of future gravitational wave measurements to inform us
on the behavior of gravity in the strong-field regime.

30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph