Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Normal Modes and No Zero Mode Theorem of Scalar Fields in BTZ Black Hole
  Spacetime
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org