Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Backscattering of electromagnetic and gravitational waves off
  Schwarzschild geometry
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph