Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Curvature properties of Robinson-Trautman metric
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat