Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Spectral element modeling of three dimensional wave propagation in a
  self-gravitating Earth with an arbitrarily stratified outer core
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio