Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Spontaneous Emission from a Two-Level Atom in a Rectangular Waveguide
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat