Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Connection by geodesics on globally hyperbolic spacetimes with a
  lightlike Killing vector field   Given a globally hyperbolic spacetime endowed with a complete lightlike
Killing vector field and a complete Cauchy hypersurface, we characterize the
points which can be connected by geodesics. A straightforward consequence is
the geodesic connectedness of globally hyperbolic generalized plane waves with
a complete Cauchy hypersurface.

23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org