Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Master equation solutions in the linear regime of characteristic
  formulation of general relativity
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs