Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Optical caustics of Kerr spacetime: the full structure
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph